AU2014266118A1 - Antibody specifically binding to HER2 - Google Patents

Abstract

The present invention relates to a novel HER2 antibody for concomitant administration which is used for preventing or treating cancer. The antibody of the present invention specifically binds to HER2, which is overexpressed in cancer cells (particularly, breast cancer and gastric cancer cells), and binds to an epitope different from that to which trastuzumab binds. The antibody of the present invention has a unique sequence due to a very low homology compared with the CDR sequence of known HER2-targeting antibodies. The antibody of the present invention kills cancer cells with remarkably improved cancer cell killing ability when concomitantly administered with trastuzumab, and is thus very useful for preventing or treating cancer (particularly, breast cancer and gastric cancer). The remarkable efficacy of concomitant administration of the antibody of the present invention is considered, without wishing to be bound by theory, to be due to the antibody of the present invention binding to an epitope of HER2 different from that to which trastuzumab binds, thereby inhibiting HER2 cooperatively with trastuzumab.

Description

ANTIBODIES CAPABLE OF BINDING SPECIFICALLY TO HER2 FIELD OF THE INVENTION The present invention was made with support of the Korea Institute for the 5 Advancement of Technology under Grant 1415118385 from November 1, 2011 to October 1, 2014 and management of International Cooperation Support Team of KIAT, titled as International Cooperation Technology Development Works and Innovative Epitope Discovery Platform Technology-Based Global Antibody New Drug Development, performed by AbClon, Inc. 10 This application claims priority from Korean Patent Application No. 10-2013 0055912, filed on May 16, 2013, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference. The present invention relates to HER2 (Human Epidermal Growth Factor Receptor 2) antibodies to prevent or treat HER2-related diseases, particularly, cancers. 15 DESCRIPTION OF THE RELATED ART The HER2/neu(ErbB2) gene encodes 185 kDa transmembrane glycoprotein which is one of EGFR (epidermal growth factor receptors) family members. The HER2 protein consists of an extracellular domain with 620 amino acid residues, a 20 transmembrane domain with 23 amino acid residues and an intracellular domain having tyrosine kinase activity with 490 amino acid residues (Akiyama T, et al., Science, 232(4758):1644-1646(1986)). In addition, HER2 antibodies with various characteristics are reported in a number of papers: Tagliabue et al., Int. J. Cancer 47:933-937 (1991); McKenzie et al., 25 Oncogene 4:543-548 (1989); Maier et al., Cancer Res. 51:5361-5369 (1991); Bacus et al., Molecular Carcinogenesis 3:350-362 (1990); Stancovski et al., PNAS (USA) 88:8691-8695 (1991); Bacus et al., Cancer Research 52:2580-2589 (1992); Xu et al., Int. J. Cancer 53:401-408 (1993); W094/00136; Kasprzyk et al., Cancer Research 52:2771-2776 (1992); Hancock et al., Cancer Research. 51:4575-4580 (1991); 30 Shawver et al., Cancer Res. 54:1367-1373 (1994); Arteaga et al., Cancer Res. 54:3758 3765 (1994); Harwerth et al., J. Biol. Chem. 267:15160-15167 (1992); U.S. Pat. No. 5,783,186; Kao et al., U.S. Publ. No. 2009/0285837 (2009); Ross et al., The Oncologist 8:307-325 (2003) and Klapper et al., Oncogene 14:2099-2109 (1997). Among HER2 antibodies, trastuzumab as the most commercially successful 35 antibody (commercialized as Herceptin

TM

, U.S. Pat. No. 5,821,337) has been intensively studied: Sapino, A., et al., Annals of Oncology (2007) 18: 1963-1968; Bussolati, G, et al., British Journal of Cancer (2005) 92, 1261-1267; and Glazyrin A, et al., J Histology & Cytochemistry (2007) 55(1):25-33. Even though the trastuzumab has been commercially successful, this antibody is 40 likely to show therapeutic efficacy in only 15% of breast cancer patients overexpressing HER2. Therefore, there have been attempts to improve prognosis of cancer patients being non-responsive or poor-responsive to trastuzumab by a 1 combination therapy, in the context of enhancing extent or spectrum of efficacies of trastuzumab. For instance, U.S. Pat. Appln. Pub. No. 2011-0086004 discloses a combined cancer therapy with trastuzumab and IL-21. U.S. Pat. Appln. Pub. No. 2012-0107270 5 describes trastuzumab in combination with tenascin-C targeting antibody conjugated with IL-2. U.S. Pat. Appln. Pub. No. 2005-0101618 discloses a cancer therapy with trastuzumab and erbB2 ligand. Europe Pat. Appln. Pub. No. 2134364 discloses inhibition of cancer cell proliferation by trastuzumab in combination with telomerase 10 inhibitors. WO 2008/031531 describes that trastuzumab in combination with pertuzumab may suppress cancer metastasis. Throughout this application, various patents and publications are referenced, and citations are provided in parentheses. The disclosure of these patents and 15 publications in their entities are hereby incorporated by references into this application in order to more fully describe this invention and the state of the art to which this invention pertains. TECHNOLOGICAL PROBLMES TO BE SOLOVED 20 The present inventors have made intensive researches to develop antibodies capable of preventing or treating HER2-related diseases, particularly cancers (more particularly breast cancer and stomach cancer). In particular, the present inventors have made intensive researches to develop antibodies in combination with trastuzumab capable of overcoming limitations in anticancer efficacies associated with trastuzumab 25 treatment as a single agent. As a result, the present inventors have developed novel antibodies having significant anticancer efficacies per se, and much higher efficacies in combination with trastuzumab for prevention or treatment of cancers (particularly breast cancer and stomach cancer, and more particularly HER2-expressing breast cancer and stomach cancer). 30 Accordingly, it is an object of this invention to provide an antibody to human epidermal growth factor receptor 2 (HER2) or antigen-binding fragment thereof. It is another object of this invention to provide a nucleic acid molecule coding for the present HER2 antibody or antigen-binding fragment thereof. It is still another object of this invention to provide a recombinant vector 35 carrying the nucleic acid molecule. It is further object of this invention to provide a host cell transfected with the recombinant vector. It is another object of this invention to provide a pharmaceutical composition for preventing or treating a cancer. 40 It is still another object of this invention to provide a pharmaceutical composition for inducing apoptosis. 2 Other objects and advantages of the present invention will become apparent from the detailed description to follow taken in conjugation with the appended claims and drawings. 5 DETAILED DESCRIPTION OF THIS INVETNION In a first aspect of this invention, there is provide an antibody to human epidermal growth factor receptor 2 (HER2) or antigen-binding fragment thereof, comprising: (a) a heavy chain variable region comprising a complementarity determining 10 region (CDR) H1 of SEQ ID NO:1, CDRH2 of SEQ ID NO:2 and CDRH3 represented by the following formula 1; and (b) a light chain variable region:

X

1

-X

2

-X

3

-X

4

-X

5

-X

6

-X

7 -Phe-Asp-Tyr (1) wherein Xi represents His, Asn, Ser or Ala; X 2 represents Leu, Phe, Tyr, His, Met, 15 Trp, Asn, Ile or Ala; X 3 represents Gly or Cys; X 4 represents Gly or Ser; X 5 represents Thr, Met or Ala; X 6 represents Ala, Ser, Gly or Thr; and X 7 represents Ser, Ala, Cys or Thr. The present inventors have made intensive researches to develop antibodies 20 capable of preventing or treating HER2-related diseases, particularly cancers (more particularly breast cancer and stomach cancer). In particular, the present inventors have made intensive researches to develop antibodies in combination with trastuzumab capable of overcoming limitations in anticancer efficacies associated with trastuzumab treatment as a single agent. As a result, the present inventors have developed novel 25 antibodies having significant anticancer efficacies per se, and much higher efficacies in combination with trastuzumab for prevention or treatment of cancers (particularly breast cancer and stomach cancer, and more particularly HER2-expressing breast cancer and stomach cancer). 30 The antibody of this invention has a specific binding capacity to HER2. In particular, the present antibody binds to an epitope on HER2 different from an epitope to which trastuzumab is bound. The term used herein "trastuzumab" refers to an antibody disclosed in U.S. Pat. No. 5,821,337. 35 The antibody of the invention exhibits cytotoxicity effects or proliferation inhibition effects against various HER2-expressing cancer cells. There is no intended distinction between the terms "cytotoxicity" and "proliferation inhibition" in conjunction with cancer cells, and these terms are interchangeably used herein. The term used herein "antibody" refers to HER2-specific antibodies including a 40 whole antibody as well as any antigen-binding fragment of antibodies. The whole antibody includes two full-length light chains and two full-length heavy chains, and each light chain is linked to the heavy chain by disulfide bond. The 3 heavy chain constant region includes five different isotypes (y, [a, a, 6 and F) which are classified into subgroups of 71, y2, 7 3 , 7 4 , al and a2. The light chain constant region includes two different isotypes (, and X) (Cellular and Molecular Immunology, Wonsiewicz, M. J., Ed., Chapter 45, pp. 41-50, W. B. Saunders Co. Philadelphia, 5 PA(1991); Nisonoff, A., Introduction to Molecular Immunology, 2nd Ed., Chapter 4,pp. 45-65, sinauer Associates, Inc., Sunderland, MA (1984)). Antigen-binding fragment refers to any antibody fragment capable of binding to antigen including Fab, F(ab'), F(ab') 2 , Fv and so on. Fab has one antigen-binding site which is composed of variable domains of heavy chain and light chain of the 10 antibody, a constant domain of light chain and the first constant domain (CH 1 ) of heavy chain. Fab' is different to Fab in the sense that there is a hinge region containing one or more cysteine residues at C-terminal of CH 1 domain of heavy chain. F(ab') 2 antibody is produced by forming a disulfide bond between cysteine residues of hinge region of Fab'. Fv is a minimal antibody fragment conposed of variable regions of 15 heavy chain and light chain, and recombinant technique to prepare a Fv fragment is disclosed in PCT WO 88/10649, WO 88/106630, WO 88/07085, WO 88/07086 and WO 88/09344. In two-chain, variable regions of heavy chain and light chain are linked by non-covalent bond, and in single-chain Fv, variable regions of heavy chain and light chain are generally linked by covalent bond via a peptide linker or directly linked to 20 each other at C-terminal, forming a dimer such as two-chain Fv. Such antibody fragments may be obtained using a proteolytic enzymes (e.g., a whole antibody is digested with papain to produce Fab fragments, and pepsin treatment results in the production of F(ab') 2 fragments), and may be prepared by genetic recombination techniques. 25 According to an embodiment, the antibody of this invention includes Fab antibodies and whole antibodies. In addition, the heavy chain constant region is selected from the isotypes consisting of y, [t, a, 6 or F. Preferably, the heavy chain constant region includes 71, 73 and 74 isotypes, most preferably 71 isotype. The light chain constant region may be K and X isotype, preferably, K isotype. Therefore, a 30 preferable embodiment of the present antibody is Fab or IgGI antibody comprising K light chain and 71 heavy chain. The term "heavy chain" used herein refers to both a full-length heavy chain and its portion, which includes variable domain (VH) containing the amino acid sequence of a variable region sequence for specifically binding to antigen and three constant 35 domains (CH1, CH2 and CH3). The term "light chain" used herein refers to both a full length light chain and its part, which includes variable domain (VL) containing the amino acid sequence of a variable region sequence for specifically binding to antigen and a constant domain (CL). The term used herein "CDR(complementarity determining region)" refers to an 40 amino acid sequence of hypervariable regions of heavy and light chains of immunoglobulins (Kabat et al., Sequences of Proteins of Immunological Interest, 4th Ed., U.S. Department of Health and Human Services, National Institutes of Health 4 (1987)). Each of the heavy and light chains comprises three CDRs (heavy chain (CDRH1, CDRH2 and CDRH3) and light chain (CDRL1, CDRL2 and CDRL3)). CDR provides contacting residues playing a crucial role in antibody binding to an antigen or epitope. 5 In the present antibody, CDRH3 is represented by the formula 1. In the formula 1, Xi represents His, Asn, Ser or Ala; specifically His, Asn or Ser; more specifically His or Asn; still more specifically His. In the formula 1, X 2 represents Leu, Phe, Tyr, His, Met, Trp, Asn, Ile or Ala; specifically Leu, Phe, Tyr, His, Met, Trp, Asn or Ile; more specifically Leu, Phe or 10 Tyr; still more specifically Leu. In the formula 1, X 3 represents Gly or Cys; specifically Gly. In the formula 1, X 4 represents Gly or Ser; specifically Gly. In the formula 1, X 5 represents Thr, Met or Ala; specifically Thr. In the formula 1, X 6 represents Ala, Ser, Gly or Thr; specifically Ala. 15 In the formula 1, X 7 represents Ser, Ala, Cys or Thr; specifically Ser. According to an embodiment, Xi represents His, Asn or Ser; X 2 represents Leu, Phe or Tyr; X 3 represents Gly; X 4 represents Gly; X 5 represents Thr, Met or Ala; X 6 represents Ala, Ser, Gly or Thr; and X 7 represents Ser, Ala, Cys or Thr. More specifically, Xi represents His, Asn or Ser; X 2 represents Leu, Phe or Tyr; 20 X 3 represents Gly; X 4 represents Gly; X 5 represents Thr; X 6 represents Ala; and X 7 represents Ser. Still more specifically, CDRH3 comprises the amino acid sequence selected from the group of SEQ ID NOs:3, 27-28, 32 and 39-86; still much more specifically, CDRH3 comprises the amino acid sequence of SEQ ID NOs:3, 43, 64, 67, 71, 76, 83, 25 84 or 85; most specifically, SEQ ID NO:3. According to an embodiment, the light chain variable region comprises CDRL1 of SEQ ID NO:4, CDRL2 of SEQ ID NO:5 and CDRL3 represented by the following formula 2: Y1-Y 2

-Y

3

-Y

4

-Y

5

-Y

6 -Pro-Trp-Thr (2) 30 wherein Yi represents Gln, Asp or Ala; Y 2 represents Gln, Asn, Glu or Ala; Y 3 represents Leu, Met, Asn, Ile, Ser, Thr, Ala or Lys; Y 4 represents Tyr, Ala, Ser, Arg, Val, Gly, Met or Phe; Y 5 represents Ser, Phe, Tyr, Arg, Ile, Gly, Lys, Asn, Val or Ala; and Y 6 represents Thr, Ser, Val, Ile, Ala, Gly, Asn, Glu, Phe or Leu. In the formula 2, Yi represents Gln, Asp or Ala; specifically Gln or Asp; more 35 specifically Gln. In the formula 2, Y 2 represents Gln, Asn, Glu or Ala; specifically Gln, Asn or Glu; more specifically Gln. In the formula 2, Y 3 represents Leu, Met, Asn, Ile, Ser, Thr, Ala or Lys; specifically Leu, Met, Asn, Ile, Ser or Thr; more specifically Leu, Met, Asn or Ile; still 40 more specifically Leu or Met; most specifically, Leu. In the formula 2, Y 4 represents Tyr, Ala, Ser, Arg, Val, Gly, Met or Phe; specifically Tyr or Ala. 5 In the formula 2, Y 5 represents Ser, Phe, Tyr, Arg, Ile, Gly, Lys, Asn, Val or Ala; specifically Ser, Phe, Tyr, Arg or Ile; more specifically Ser, Phe or Tyr. In the formula 2, Y 6 represents Thr, Ser, Val, Ile, Ala, Gly, Asn, Glu, Phe or Leu; specifically Thr, Ser, Val, Ile, Ala, Gly or Asn; more specifically Thr, Ser or Ala. 5 According to an embodiment, Yi represents Gln or Asp; Y 2 represents Gln; Y 3 represents Leu, Met, Asn, Ile, Ser or Thr; Y 4 represents Tyr, Ala, Ser, Arg, Val, Gly, Met or Phe; Y 5 represents Ser, Phe, Tyr, Arg or Ile; and Y 6 represents Thr, Ser, Val, Ile, Ala, Gly or Asn. More specifically, CDRL3 comprises the amino acid sequence of SEQ ID 10 NOs:6, 33-38 or 87-245; still more specifically, CDRL3 comprises the amino acid sequence of SEQ ID NOs:6, 88, 109, 131, 155, 156, 157, 178, 218, 220, 222 or 239; most specifically, SEQ ID NOs:6, 88 (hzlEll-3), 218 (hzlEll-133) or 239 (hzlEll 154). According to an embodiment, the heavy chain variable region comprises the 15 amino acid sequence of SEQ ID NOs:8 (lEl1) or 24 (hzlEl1). According to an embodiment, the light chain variable region comprises the amino acid sequence of SEQ ID NOs:10 (lEll), 26 (hzlEll), 247 (hzlEll-3), 249 (hzlEl1-133) or 251 (hzlEl1-154). As demonstrated in Examples, while the antibody of the present invention is 20 specifically bound to sub-domain 4 among extracellular domains of HER2, the present antibody is bound to an epitope on sub-domain 4 being different from an epitope of trastuzumab. The present HER2 antibody or its antigen-binding fragment includes variants of amino acid sequences set forth in the appended Sequence Listing so long as they are 25 capable of specifically recognizing HER2. For example, amino acid sequences of antibodies may be altered to improve binding affinity and/or the other biological characteristics of antibodies. For example, such alterations include deletion, insertion and/or substitution of amino acid residues of antibodies. Such amino acid variations may be provided on the basis of a relative similarity 30 of amino acid side chains, e.g., hydrophobicity, hydrophilicity, charge and size. By the analysis for size, shape and type of the amino acid side chains, it could be clear that all of arginine, lysine and histidine residues are those having positive charge; alanine, glycine and serine have a similar size; phenylalanine, tryptophan and tyrosine have a similar shape. Accordingly, based on these considerable factors, arginine, lysine and 35 histidine; alanine, glycine and serine; and phenylalanine, tryptophane and tyrosine may be considered to be functional equivalents biologically. For introducing variations, a hydropathic index of amino acids may be considered. Based on the hydrophobicity and the charge, the hydropathic index is given to each amino acid: isoleucine (+4.5); valine (+4.2); leucine (+3.8); 40 phenylalanine (+2.8); cysteine (+2.5); methionine (+1.9); alanine (+1.8); glycine (-0.4); threonine (-0.7); serine (-0.8); tryptophane (-0.9); tyrosine (-1.3); proline (-1.6); histidine (-3.2); glutamate (-3.5); glutamine (-3.5); aspartate (-3.5); asparagin (-3.5); 6 lysine (-3.9); and arginine (-4.5). For providing an interactive biological function of proteins, the hydropathic index of the amino acid is very important. It is well known to one of skill in the art that variants can possess a similar biological activity only where proteins are replaced with 5 amino acids having similar hydropathic index. Where variations are introduced based on the hydropathic index, the substitution is preferably performed between amino acid residues having no more than ±2 difference in hydropathic index values more preferably within ± 1, much more preferably within ±0.5. It would be also obvious to those of skill in the art that substitutions of amino 10 acids with other amino acids having similar hydrophilicity values may result in the generation of variants having biologically equivalent activities. As disclosed in U.S. Pat. No. 4,554,101, each amino acid residue is assigned the following hydrophilicity values: arginine (+3.0); lysine (+3.0); aspartate (+3.0±1); glutamate (+3.0±1); serine (+0.3); asparagin (+0.2); glutamine (+0.2); glycine (0); threonine (-0.4); proline ( 15 0.5±1); alanine (-0.5); histidine (-0.5); cysteine (-1.0); methionine (-1.3); valine (-1.5); leucine (-1.8); isoleucine (-1.8); tyrosine (-2.3); phenylalanine (-2.5); tryptophane ( 3.4). Where variations are intended to introduced based on the hydrophilicity value, the substitution is preferably performed between amino acid residues having no more 20 than ±2 difference in hydrophilicity values, more preferably within ±1, much more preferably within ±0.5. The alteration of amino acid residues without substantially impairing protein activity is well known to one skilled in the art (H. Neurath, R. L. Hill, The Proteins, Academic Press, New York, 1979). Such amino acid alteration includes substitutions 25 of Ala/Ser, Val/Ile, Asp/Glu, Thr/Ser, Ala/Gly, Ala/Thr, Ser/Asn, Ala/Val, Ser/Gly, Thr/Phe, Ala/Pro, Lys/Arg, Asp/Asn, Leu/Ile, Leu/Val, Ala/Glu and Asp/Gly, but not limited thereto. Considering the afore-mentioned variations having biologically equivalent activities, it could be understood that either antibody of this invention or the nucleic 30 acid encoding the same includes substantially identical sequences to the sequences set forth in the appended Sequence Listing. The substantially identical sequences refers to those showing preferably at least 61%, more preferably at least 70%, still more preferably at least 80%, most preferably at least 90% nucleotide similarity to the sequences of the appended Sequence Listing, as measured using one of the 35 conventionally used sequence comparison algorithms. Methods of alignment of sequences for comparison are well-known in the art. Various programs and alignment algorithms are described in: Smith and Waterman, Adv. Appl. Math. 2:482(1981); Needleman and Wunsch, J. Mol. Bio. 48:443(1970); Pearson and Lipman, Methods in Mol. Biol. 24: 307-31(1988); Higgins and Sharp, Gene 73:237-44(1988); Higgins and 40 Sharp, CABIOS 5: 151-3(1989); Corpet et al., Nuc. Acids Res. 16:10881-90(1988); Huang et al., Comp. Appl. BioSci. 8:155-65(1992); and Pearson et al., Meth. Mol. Biol. 24:307-31(1994). The NCBI Basic Local Alignment Search Tool (BLAST) (Altschul 7 et al., J. Mol. Biol. 215: 403-10(1990)) is available from several sources, including the National Center for Biological Information (NBCI, Bethesda, Md.) and on the Internet, for use in connection with the sequence analysis programs for blastp, blasm, blastx, tblastn and tblastx. It can be accessed at http://www.ncbi.nlm.nih.gov/BLAST/. A 5 description of how to determine sequence identity using this program is available at http://www.ncbi.nlm.nih.gov/BI-AST/blast help.html. The antibody of the present invention includes, but not limited to, monoclonal antibody, multispecific antibody, human antibody, humanized antibody, chimeric antibody, single-chain Fvs (scFV), single-chain antibody, Fab fragment, F(ab') 10 fragment, disulfide-linked Fvs (sdFV) and anti-idiotype (anti-Id) antibody, and epitope-binding fragment thereof. The CDR sequences of the present antibodies exhibit low similarity to CDR sequences of publicly known antibodies, addressing that the CDR sequences are unique. For example, antibodies disclosed in U.S. Pat. Nos. 7,329,737 and 7,993,646 15 that have the highest similarity to the present antibodies in BLAST search (http://www.ncbi.nlm.nih.gov/BLAST/) show similarity of less than 50% to the CDR sequences of lEl1 antibody, a mother antibody, and furthermore are bound to hK-1 being different from the target of the present antibodies. Accordingly, the amino acid sequences of the present antibodies may be 20 considered novel and unique. In another aspect of this invention, there is provided a nucleic acid molecule encoding the present antibody or antigen-binding fragment thereof. The term used herein "nucleic acid molecule" comprehensively refers to a 25 DNA (gDNA and cDNA) or RNA molecule, and the basic nucleotides of nucleic acid molecule also include analogues with modified sugar or base as well as natural nucleotides (Scheit, Nucleotide Analogs, John Wiley, New York (1980); Uhlman and Peyman, Chemical Reviews, 90:543-584 (1990)). The sequence of the present nucleic acid molecule encoding the variable regions of heavy and light chain could be 30 modified. Such modification includes addition, deletion or non-conservative or conservative substitution of nucleotide. According to an embodiment, the nucleic acid molecule encoding the heavy chain variable region comprises a nucleotide sequence of SEQ ID NO:7 or 23. According to an embodiment, the nucleic acid molecule encoding the light 35 chain variable region comprises a nucleotide sequence of SEQ ID NO:9, 25, 246, 248 or 250. The nucleic acid molecule coding for the present HER2 antibody also includes a nucleotide sequence sharing substantial homology with the above nucleotide sequence. The substantial homology means the nucleotide sequence sharing homology 40 of at least 80%, more preferably 90% and most preferable 95% by sequence alignment analysis using maximal alignment between the nucleotide sequence of this invention and other random sequences and algorithm ordinarily known to those skilled in the art. 8 In still another aspect of this invention, there is provided a recombinant vector comprising the present nucleic acid molecule described above. The term used herein "vector" is a tool for expressing a target gene in a host 5 cell, including a plasmid vector; a cosmid vector; and a virus vector such as a bacteriophage vector, an adenovirus vector, a retrovirus vector and an adeno associated virus vector. According to an embodiment, the nucleic acid molecules encoding the variable regions of light and heavy chains are operatively linked to a promoter. 10 The term used herein "operatively linked" refers to functional linkage between a nucleic acid expression control sequence (e.g., a promoter, signal sequence, or array of transcription factor binding sites) and a second nucleic acid sequence, wherein the expression control sequence affects transcription and/or translation of the nucleic acid corresponding to the second sequence. 15 The recombinant vectors of this invention may be constructed by various methods known to those skilled in the art and its practical methods are described in Sambrook et al., Molecular Cloning, A Laboratory Manual, Cold Spring Harbor Laboratory Press (2001), which is herein incorporated by reference. Typically, the vector of this invention may be constructed as cloning or 20 expression vector. In addition, the vector of this invention may be constructed using a prokaryotic or eukaryotic cell as a host cell. For instance, where the expression vector is constructed for eukaryotic host cell, a promoter derived from the genome of mammalian cells (e.g., metallothionein promoter, -actin promoter, human hemoglobin promoter and human muscle creatine 25 promoter) or mammalian virus (e.g., adenovirus late promoter; vaccinia virus 7.5K promoter, SV40 promoter, cytomegalovirus promoter, tk promoter of HSV, mouse mammary tumor virus (MMTV) promoter, LTR promoter of HIV, moloney virus promoter, Epstein-Barr virus (EBV) promoter and Rous sarcoma virus (RSV) promoter) may be used. The vector generally contains a polyadenylation sequence as a 30 transcription terminator. The vector of this invention may be fused with other sequences to purify an antibody expressed. For example, a sequence to be fused includes glutathione-S transferase (Pharmacia, USA), maltose-binding protein (NEB, USA), FLAG (IBI, USA) and 6x His (hexahistidine; Quiagen, USA) and so on. 35 Since the protein expressed by the vector of the present invention is antibody, the expressed antibody could be also purified throughout protein A column in an easy manner without additive sequences for purification. The expression vector of this invention includes an antibiotics-resistance gene known to those ordinarily skilled in the art as a selection marker, for example resistant 40 genes against ampicillin, gentamycin, carbenicillin, chloramphenicol, streptomycin, kanamycin, geneticin, neomycin and tetracycline. In further aspect of this invention, there is provided a host cell transformed 9 with the above-described recombinant vector. The host cells in which the present vector is stably and successively cloned and expressed, also utilize any one known to those skilled in the art, for example, suitable eukaryotic host cell including COS7 cell (monkey kidney cell), NSO cell, SP2/0, CHO 5 (Chinese hamster ovary) cell, W138, BHK (baby hamster kidney) cell, MDCK, myeloma cell line, HuT 78 cell and HEK-293 cell, but not limited thereto. In another aspect of this invention, there is provided a pharmaceutical composition for preventing or treating a cancer, comprising: (a) a pharmaceutically effective amount of the present antibody to HER2 or antigen-binding fragment thereof; 10 and (b) a pharmaceutically acceptable carrier. Since the present pharmaceutical composition comprises the HER2 antibody of the present invention or its antigen-binding fragment as an active ingredient, the common descriptions between them are omitted in order to avoid undue redundancy leading to the complexity of this specification. 15 As addressed in Examples, the HER2 antibody of the present invention in combination with trastuzumab kills cancer cells (particularly, breast cancer cells, more particularly, HER2-expressing breast cancer cells) with significantly enhanced cytotoxicity and therefore very effective in therapy of cancer (particularly, breast cancer and stomach cancer, more particularly, HER2-expressing breast cancer and 20 stomach cancer). According to an embodiment, the pharmaceutical composition further comprises trastuzumab. The cancer to be prevented or treated by the present composition includes various cancers known to one of skill in the art, for example, breast cancer, ovarian cancer, stomach cancer, lung cancer, liver cancer, bronchus cancer, nasopharyngeal 25 cancer, laryngeal cancer, pancreatic cancer, bladder cancer, colorectal cancer, colon cancer, cervical cancer, brain cancer, prostate cancer, bone cancer, head and neck cancer, skin cancer, thyroid cancer, parathyroid cancer or ureteral cancer. Specifically, the cancer to be prevented or treated by the composition is HER2 expressing cancer, more specifically HER2-expressing breast cancer or stomach cancer. 30 In still another aspect of this invention, there is provided a pharmaceutical composition for inducing apoptosis, comprising: (a) a pharmaceutically effective amount of the present antibody to HER2 or antigen-binding fragment thereof; and (b) a pharmaceutically acceptable carrier. According to an embodiment, the pharmaceutical composition induces 35 apoptosis for prevention or treatment of a hyperproliferative disease; wherein the hyperproliferative disease is cancer, hyperplasia, keloid, Cushing syndrome, primary aldosteronism, erythroplakia, polycythemia vera, leukoplakia, hyperplastic scar, lichen planus, lentiginosis, arteriosclerosis , atherosclerosis, restenosis or stenosis. The pharmaceutically acceptable carrier may be conventional one for 40 formulation, including lactose, dextrose, sucrose, sorbitol, mannitol, starch, rubber arable, potassium phosphate, arginate, gelatin, potassium silicate, microcrystalline cellulose, polyvinylpyrrolidone, cellulose, water, syrups, methyl cellulose, 10 methylhydroxy benzoate, propylhydroxy benzoate, talc, magnesium stearate, and mineral oils, but not limited thereto. The pharmaceutical composition according to the present invention may further include a lubricant, a humectant, a sweetener, a flavoring agent, an emulsifier, a suspending agent, and a preservative. Details of suitable 5 pharmaceutically acceptable carriers and formulations can be found in Remington's Pharmaceutical Sciences (19th ed., 1995), which is incorporated herein by reference. The pharmaceutical composition according to the present invention may be parenterally administered, for example, by intravenous, subcutaneous, intramuscular, intraperitoneal, local, nasal, pulmonary or rectal administration. 10 A suitable dose of the pharmaceutical composition of the present invention may vary depending on pharmaceutical formulation methods, administration methods, the patient's age, body weight, sex, severity of diseases, diet, administration time, administration route, an excretion rate and sensitivity to the pharmaceutical composition. Preferably, the pharmaceutical composition of the present invention is 15 administered with a daily dose of 0.0001-100 mg/kg (body weight). The term "pharmaceutically effective amount" refers to an amount suitable to prevent or treat cancer. According to the conventional techniques known to those skilled in the art, the pharmaceutical composition may be formulated with pharmaceutically acceptable 20 carrier and/or excipient, finally providing several forms including a unit dose form and a multi-dose form. Formulation may be oil or aqueous media, resuspension or emulsion, extract, powder, suppository, granule, tablet or capsule and further comprise dispersant or stabilizer. The antibody of the present invention may be used to diagnose HER2 25 expressing related disorders, diseases or conditions. In further aspect of this invention, there is provided a kit for diagnosing a HER2-expressing related disorder, disease or condition comprising the present antibody to HER2 or antigen-binding fragment thereof. The HER2-expressing related disorder, disease or condition is particularly 30 cancer, for example, breast cancer, ovarian cancer, stomach cancer, lung cancer, liver cancer, bronchus cancer, nasopharyngeal cancer, laryngeal cancer, pancreatic cancer, bladder cancer, colorectal cancer, colon cancer, cervical cancer, brain cancer, prostate cancer, bone cancer, head and neck cancer, skin cancer, thyroid cancer, parathyroid cancer or ureteral cancer. Specifically, the diagnosis kit of the present invention is used 35 to diagnose HER2-expressing cancer, more specifically HER2-expressing breast cancer or stomach cancer. The antibody of the present invention may be used to analyze a drug responsiveness of the present antibody in a patient. 40 In another aspect of this invention, there is provided a kit for analyzing a drug responsiveness comprising the present antibody. The analysis kit of the present invention is used to evaluate a drug 11 responsiveness of the present antibody in a patient. For example, where cancer cells obtained from a patient are incubated with the antibody of this invention and the antibody is elucidated to be bound to the cells, the patient is determined to possess a drug responsiveness of the present antibody. 5 Since the present kit comprises antibodies, it may be fabricated for immunoassay or immunostaining. The immunoassay or immunostaining format includes, but not limited to, radioimmunoassay, radioimmuno-precipitation, enzyme linked immunosorbent assay (ELISA), capture-ELISA, inhibition or competition assay, sandwich assay, flow cytometry, immunofluorescence staining and immunoaffinity 10 purification, but not limited thereto. The immunoassay or immunostaining procedures can be found in Enzyme Immunoassay, E. T. Maggio, ed., CRC Press, Boca Raton, Florida, 1980; Gaastra, W., Enzyme-linked immunosorbent assay (ELISA), in Methods in Molecular Biology, Vol. 1, Walker, J.M. ed., Humana Press, NJ, 1984; and Ed Harlow and David Lane, Using Antibodies, A Laboratory Manual, Cold Spring Harbor 15 Laboratory Press, 1999, which are incorporated herein by reference. For example, according to the radioimmunoassay method, the radioisotope (e.g., C 4, Ii2s p32 and S ) labeled antibody may be used to identify HER2 on the surface of cancer cells. According to the ELISA method, the specific example of the present method may comprise the steps of: (i) coating a surface of a solid substrate with a 20 biosample to be analyzed; (ii) incubating the biosample with the HER2 antibody of this invention as a primary antibody; (iii) incubating the resultant of step (ii) with a secondary antibody conjugated with an enzyme; and (iv) measuring the activity of the enzyme. The solid substrate may be hydrocarbon polymers (e.g., polystyrene and 25 polypropylene), glass, metals or gels. Most preferably, the solid substrate is a microtiter plate. The enzyme conjugated to the secondary antibody includes an enzyme catalyzing colorimetric, fluorometric, luminescence or infra-red reactions, for example alkaline phosphatase, -galactosidase, horseradish peroxidase, luciferase and 30 Cytochrome P 450 . Where using alkaline phosphatase, bromochloroindolylphosphate (BCIP), nitro blue tetrazolium (NBT), naphthol-AS-B1-phosphate and ECF (enhanced chemifluorescence) may be used as a substrate; in the case of using horseradish peroxidase, chloronaphtol, aminoethylcarbazol, diaminobenzidine, D-luciferin, lucigenin (bis-N-methylacridinium nitrate), resorufin benzyl ether, luminol, Amplex 35 Red reagent (10-acetyl-3,7-dihydroxyphenoxazine, Pierce), HYR (p phenylenediamine-HCl and pyrocatechol), TMB (3,3,5,5-tetramethylbenzidine), ABTS (2,2-Azine-di[3-ethylbenzthiazoline sulfonate]), o-phenylenediamine (OPD) and naphthol/pyronine, glucose oxidase and t-NBT (nitroblue tetrazolium) and m-PMS (phenzaine methosulfate) may be used as a substrate. 40 According to the capture-ELISA method, the specific example of the present method may comprise the steps of: (i) coating a surface of a solid substrate with the HER2 antibody as a capturing antibody; (ii) incubating the capturing antibody with a 12 biosample to be analyzed; (iii) incubating the resultant of step (ii) with the HER2 antibody conjugated with a label generating a detectable signal as a detecting antibody; and (iv) measuring the signal generated from the label. The detecting antibody has a label generating a detectable signal. The label 5 includes, but not limited to, a chemical (e.g., biotin), an enzymatic (e.g., alkaline phosphatase, j-galactosidase, horseradish peroxidase, and Cytochrome P 4 5 0 ), a radioactive (e.g., C 4, I125 p32 and S ), a fluorescent (e.g., fluorescein), a luminescent, a chemiluminescent and a FRET (fluorescence resonance energy transfer) label. Various labels and methods for labeling antibodies may be found in Ed Harlow and 10 David Lane, Using Antibodies, A Laboratory Manual, Cold Spring Harbor Laboratory Press, 1999. The measurement of the enzyme activity or signal in ELISA and capture ELISA can be carried out by various processes well known in the art. Where biotin is used as labels, the detection may be performed using streptavidin. Where luciferase is 15 used, the detection may be performed using luciferin. The biosample applicable to the present kit includes, but not limited to, cells, tissues, tissue-derived extracts, lysate or purified product, blood, plasma, serum, lymph and ascitic fluid. 20 The antibody of the present invention may be used for in vivo or in vitro imaging. In another aspect of this invention, there is provided an imaging composition comprising the antibody of the present invention and a signal-generating label conjugated to the antibody. The signal-generating label includes, but not limited to, T1 contrast agent (e.g., 25 Gd chelate compound), T2 contrast agent (e.g., superparamagnetic materials (e.g., magnetite, Fe 3 0 4 , y-Fe 2 0 3 , manganese ferrite, cobalt ferrite and nickel ferrite)), 11 15 13 32 35 44 45 118 136 198 20 205 radioisotope (e.g., C, 0, N, P , S , Sc, Ti, 1, La, T18, 20T1, Bi and 206 Bi), fluorescent materials (e.g., fluorescein, phycoerythrin, rhodamine, lissamine, Cy3 and Cy5), chemiluminescent materials, magnetic particles, mass labels and 30 electron dense particles. Although the antibody of the present invention alone is useful in cancer therapy, it may be provided in the form of ADC (antibody drug conjugate) by conjugating with other drug because the antibody is able to target HER2-expressing cells. 35 Therefore, in another aspect of this invention, there is provided an ADC (antibody drug conjugate) comprising the antibody of the present invention and a drug conjugated with the antibody. The drug conjugated with the antibody includes, but not limited to, chemicals, radionuclides, immunotherapeutics, cytokines, chemokines, toxins, biological agents 40 and enzyme inhibitors, specifically anticancer drugs as follows: acivicin, aclarubicin, acodazole, acronycine, adozelesin, alanosine, aldesleukin, allopurinol sodium, altretamine, aminoglutethimide, amonafide, ampligen, amsacrine, androgens, 13 anguidine, aphidicolin glycinate, asaley, asparaginase, 5-azacitidine, azathioprine, Bacillus calmette-guerin (BCG), Baker's Antifol, beta-2'-deoxythioguanosine, bisantrene HCl, bleomycin sulfate, busulfan, buthionine sulfoximine, BWA773U82, BW 502U83/HCl, BW 7U85 mesylate, ceracemide, carbetimer, carboplatin, 5 carmustine, chlorambucil, chloroquinoxaline-sulfonamide, chlorozotocin, chromomycin A3, cisplatin, cladribine, corticosteroids, Corynebacterium parvum, CPT-11, crisnatol, cyclocytidine, cyclophosphamide, cytarabine, cytembena, dabis maleate, dacarbazine, dactinomycin, daunorubicin HCl, deazauridine, dexrazoxane, dianhydrogalactitol, diaziquone, dibromodulcitol, didemnin B, diethyldithiocarbamate, 10 diglycoaldehyde, dihydro-5-azacytidine, doxorubicin, echinomycin, dedatrexate, edelfosine, eflornithine, Elliott's solution, elsamitrucin, epirubicin, esorubicin, estramustine phosphate, estrogens, etanidazole, ethiofos, etoposide, fadrazole, fazarabine, fenretinide, filgrastim, finasteride, flavone acetic acid, floxuridine, fludarabine phosphate, 5-fluorouracil, FluosolTM, flutamide, gallium nitrate, 15 gemcitabine, goserelin acetate, hepsulfam, hexamethylene bisacetamide, homoharringtonine, hydrazine sulfate, 4-hydroxyandrostenedione, hydrozyurea, idarubicin HCl, ifosfamide, 4-ipomeanol, iproplatin, isotretinoin, leucovorin calcium, leuprolide acetate, levamisole, liposomal daunorubicin, liposome encapsulated doxorubicin, lomustine, lonidamine, maytansine, mechlorethamine hydrochloride, 20 melphalan, menogaril, merbarone, 6-mercaptopurine, mesna, methanol extraction residue of Bacillus calmette-guerin, methotrexate, N-methylformamide, mifepristone, mitoguazone, mitomycin-C, mitotane, mitoxantrone hydrochloride, monocyte/macrophage colony-stimulating factor, nabilone, nafoxidine, neocarzinostatin, octreotide acetate, ormaplatin, oxaliplatin, paclitaxel, pala, 25 pentostatin, piperazinedione, pipobroman, pirarubicin, piritrexim, piroxantrone hydrochloride, PIXY-321, plicamycin, porfimer sodium, prednimustine, procarbazine, progestins, pyrazofurin, razoxane, sargramostim, semustine, spirogermanium, spiromustine, streptonigrin, streptozocin, sulofenur, suramin sodium, tamoxifen, taxotere, tegafur, teniposide, terephthalamidine, teroxirone, thioguanine, thiotepa, 30 thymidine injection, tiazofurin, topotecan, toremifene, tretinoin, trifluoperazine hydrochloride, trifluridine, trimetrexate, TNF (tumor necrosis factor), uracil mustard, vinblastine sulfate, vincristine sulfate, vindesine, vinorelbine, vinzolidine, Yoshi 864, zorubicin, cytosine arabinoside, etoposide, melphalan, taxotere and taxol. 35 EFFECTS OF THIS INVETNION The features and advantages of the present invention will be summarized as follows: (a) The antibody of the invention binds specifically to HER2 over-expressed in cancer cells (particularly, breast cancer and stomach cancer cells), specifically to an 40 epitope on HER2 being different from epitope for trastuzumab. (b) The CDR sequences of the present antibodies exhibit low similarity to CDR sequences of publicly known HER2 antibodies, addressing that the CDR sequences are 14 unique. (c) The antibodies of the present invention in combination with trastuzumab kill cancer cells with significantly enhanced cytotoxicity and therefore very effective in therapy of cancer (particularly, breast cancer and stomach cancer). 5 (d) Without wishing to be bound by theory, the enhanced efficacies of the combined therapy would address that the antibodies of the present invention bind to epitope on HER2 being different from epitope for trastuzumab, and inhibit HER2 in a cooperative manner with trastuzumab. (e) The antibodies of the present invention capable of inducing apoptosis can be 10 used for prevention or treatment of hyperproliferative diseases. (f) The present invention can also be useful in cancer diagnosis, drug responsiveness analysis, imaging and ADC (antibody drug conjugate) as well as cancer therapy. 15 BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows genetic maps of pcDNA3.3-IgG Heavy vector and pOptiVEC IgG Kappa vector. FIGS. 2A and 2B are graphs respectively showing the proliferation inhibitory effects of a single treatment by lEll antibody and a combined treatment of lEll 20 antibody and trastuzumab against NCI-N87 cancer cell line and BT-474 cancer cell line. TRA, PER, and hIgG respectively indicate trastuzumab, pertuzumab, and human IgG (negative control). FIGS. 3A and 3B show that lEll antibody binds to a domain of HER2 sub domain which is different from the binding domain of trastuzumab'. FIGS. 3A and 25 3B respectively show the results of SPR analysis and ELISA analysis. FIG. 4A shows the result of ELISA analysis to examine whether lEll antibody binds specifically to HER2 among ErbB family proteins to which HER2 belongs. Cetuximab (CET) was used as a control antibody against EGFR protein. FIG. 4B shows the result of ELISA analysis to examine whether lEll antibody 30 binds to HER2 other than humans. FIG. 5A shows the analysis result of the percentage of cancer cells where apoptosis occurred when NCI-N87 cells were treated with lEll antibody or trastuzumab alone or in combination thereof. FIG. 5B shows the analysis result of the percentage of cancer cells where 35 apoptosis occurred when BT-474 cells were treated with lEll antibody or trastuzumab alone or in combination thereof. FIG. 5C shows the result of cell viability analyses 24 hours and 48 hours after treating NCI-N87 cells with lEll antibody or trastuzumab alone or in combination thereof. The control group shows the viability of cells treated with PBS only, the 40 solvent for the antibodies. FIG. 5D shows the analysis result of Caspase-3/7 activity, 24 hours after treating NCI-N87 cells with lEll antibody or trastuzumab alone or in combination 15 thereof. The control group shows the viability of cells treated with PBS only, the solvent for the antibodies. FIG. 6A shows the result of western blot analysis illustrating the decrease in HER2 downstream signaling by treatment with lEll antibody or trastuzumab alone or 5 in combination thereof. FIG. 6B is a graph showing the inhibitory effect for the heterodimerization induced cell proliferation by the treatment with 1E 11 antibody or trastuzumab alone or in combination thereof. A negative control (Negative ctrl) shows the viability of cells neither treated with ligands nor antibodies, and a positive control (Positive ctrl) shows 10 the viability of cells treated with ligands only without treatment with antibodies. FIGS. 7A through 7C show the tumor cell growth inhibitory effects in an NCI N87 xenograft animal model by the treatment with lEll antibody or trastuzumab alone or in combination thereof. FIG. 7A shows a graph illustrating the change in tumor volume, FIG. 7B shows a graph illustrating the change in tumor weight, and FIG. 15 7C shows an image illustrating the staining result of tumor tissues. Control Ab is palivizumab. FIGS. 8A and 8B are graphs respectively showing the proliferation inhibitory effects for NCI-N87 cancer cell line and OE- 19 cancer cell line, by a single treatment with hzlEll antibody, which is a humanized antibody, and a combined treatment of 20 hzlE11 antibody and trastuzumab. FIG. 9 shows the tumor cell growth inhibitory effect in an NCI-N87 xenograft animal model by the treatment with hzlEll antibody or trastuzumab alone or in combination thereof. Control Ab is palivizumab. FIGS. 10A and 10B respectively show alanine scanning results of CDRH3 and 25 CDRL3 of the hz 1 E11 antibody. FIGS. 11A through 11F are graphs showing the proliferation inhibitory effects for NCI-N87, OE-19, and BT-474 cancer cell lines by a single treatment with hzlEll 3, hzlEll-133, and hzlEll-154 antibodies, which are affinity-improved humanized antibodies, and a combined treatment of trastuzumab therewith. 30 The present invention will now be described in further detail by examples. It would be obvious to those skilled in the art that these examples are intended to be more concretely illustrative and the scope of the present invention as set forth in the appended claims is not limited to or by the examples. 35 EXAMPLES EXAMPLE 1: DEVELOPMENT OF HER2 ANTIBODIES For preparing antibodies, the extracellular domain (ECD) of HER2 protein was produced using animal cells and then used it as an antigen. The DNA, where a hinge 40 region of human IgG1 and Fc portion (CH2-CH3) were bound to the C-terminus of ECD, was cloned using HindIll and BamHI restriction enzymes. Then, the cloned 16 vector was transiently transfected into the FreeStyleTM 293F (Invitrogen, Cat. No. R790-07) cell using polyethyleneimine (Polyscience Inc., Cat. No. 23966), and HER2 ECD Fc fusion protein was purified from the cell culture using Protein-A Ceramic HyperD F resin (PALL, Cat No. 20078-028). The purified protein was quantitated 5 using a Protein assay dye (Bio-Rad, Cat. No. 500-0006), subjected to SDS-PAGE, and its concentration and purity were confirmed via Coomassie staining. 100 tg of the purified protein antigen was mixed with Freund's adjuvant (Sigma, Cat. No. F5506) and then intraperitoneally injected into BALB/c mice (DBL Co., Ltd., Korea). In two weeks, 100 tg of the antigen was diluted in PBS and injected again, and three days 10 thereafter, the spleen of the mouse was taken out and lymphocytes were isolated therefrom. The isolated lymphocytes were mixed with the myeloma cell line SP2/0 Agl4 (ATCC, Cat. No. CRL-1581) at a 5:1 ratio, and fused using PEG-1500 (Roche, Cat. No. 783641). The fused cells were cultured in a medium containing the HAT supplement (Sigma, Cat. No. H0262), and the fused cells (hybridoma) were selectively 15 sorted out and cultured. The thus-obtained hybridoma cells were examined via ELISA assay to determine whether they were the cells producing antibodies that bind to antigens. HER2-ECD-Fc or ChromPure human IgG (hIgG, Jackson Immunoresearch Lab. Inc., Cat. No. 009-000-003) was immobilized at room temperature to a Costar 96-well plate 20 (Coming, Cat. No. 3590) at a concentration of 1 [tg/mL for 1 hour. The resultant was washed 3 times with TBS-T (0.05% Triton X-100) and then blocked at room temperature with 300 [tL of TBS-T/SM (2% skim milk) for 30 minutes. The blocked plate was washed 3 times and added with a hybridoma culture broth, and allowed to bind to antibodies at 37 0 C for 1 hour. After washing the resultant 3 times, anti-mouse 25 IgG-HRP (Pierce, Cat. No. 31439) as a secondary antibody was diluted in TBS-T/SM at a 1:5,000 ratio and allowed to bind thereto at 37 0 C for 1 hour. After washing the resultant 3 times, TMB (SurModics, Cat. No. TMBC-1000-01) was added thereto and allowed to develop a color at room temperature for 5 minutes and added with 1 N sulfuric acid (DukSan, Cat. No. 254) to stop the color development. The absorbance 30 was measured at 450 nm using Victor X3 (PerkinElmer, Cat. No. 2030-0030), and the antibodies that bind specifically to HER2-ECD-Fc were selected. Since HER2 is a protein expressed on the cell surface, it was examined whether the developed antibodies were bound to HER2-overexpressing cells via cell-based ELISA assay. The HER2-overexpressing ovary cancer cell line, SKOV-3 (Korean 35 Cell Line Bank (KCLB), Cat. No. 30077) was aliquoted into the Costar 96-well cell culture plate (Corning, Cat. No. 3595) at a concentration of 10,000 cell/well and cultured for 24 hours. On the following day, after removing the cell culture supernatant, the resultant was washed with PBS 3 times, added with hybridoma culture broth, and cultured further at 37 0 C for 2 hours. After washing the resultant 3 times 40 with TBS-T, goat anti-mouse IgG-HRP as a secondary antibody which was diluted in PBS/FBS (3% FBS) at a 1:5,000 ratio, added thereto, and treated at room temperature 17 for 1 hour. After washing the resultant 3 times with TBS-T, it was allowed to develop a color using TMB. 61 clones showing higher absorbance than that of the SP2/0 cell culture as a negative control were selected. 5 EXAMPLE 2: COMPARISON OF INHIBITORY EFFECTS OF DEVELOPED ANTIBODIES AGAINST THE GROWTH OF BREAST CANCER CELLS In order to perform a cell viability assay for confirming the inhibitory effect against the proliferation of breast cancer cells, the antibodies from the hybridoma culture broth were purified. The hybridoma was cultured in a culture medium 10 containing 3% FBS, and the antibodies in the form of IgG were purified using Protein A resin. The purified antibodies were quantitated via BCA assay (Pierce, Cat. No. 23227), subjected to SDS-PAGE, and their concentration and purity were confirmed via Coomassie staining. Cell viability assay was performed by a single treatment or a combined 15 treatment along with trastuzumab regarding BT-474, the representative breast cancer cell line, and NCI-N87 cell line, the representative stomach cancer cell line, where HER2 is overexpressed. For the combined treatment, a mixture of the developed antibodies and trastuzumab mixed at a 1:1 ratio (weight ratio) was used. To the 96 well plate were aliquoted BT-474 (ATCC, Cat. No. HTB-20, 10,000 cells/well) and 20 NCI-N87 (ATCC, Cat No. CRL-5822, 10,000 cells/well) cells, and cultured for 24 hours. The purified antibodies were respectively treated to have a concentration of 5 [tg/mL, and BT-474 and NCI-N87 cell lines were cultured further for 4 days. For cell viability assay, CCK-8 (Dojindo, Cat. No. CK-04-13) was added to a final concentration of 10%, treated at 37'C for 3 hours, and their absorbance was measured. 25 The relative viability was calculated relative to the absorbance of the well not treated with the antibody, which was set at 100% of viability. Based on the above, lEll antibody was selected. EXAMPLE 3: ANALYSIS OF ANTIBODY SEQUENCE 30 For antibody sequence assay, a phage Fab antibody library was constructed using the respective hybridoma RNA, and a three-step panning was proceeded to obtain a phage that binds to the HER2-ECD-Fc (Phage display: a laboratory manual, Carlos Barbas III, et al., Cold Spring Harbor Laboratory Press). After culturing the hybridoma, RNA was isolated using SV Total RNA Isolation System (Promega, Cat. 35 No. Z3100) and a cDNA was synthesized therefrom. Using a known primer set (see: Phage display: a laboratory manual, Carlos Barbas III, et al., Cold Spring Harbor Laboratory Press), the variable region of the antibody was amplified, and cloned into pComb3X vector (Barbas laboratory, The Scripps Research Institute) using SfiI 18 restriction enzyme after ligating to human Ck and CHi, and then transformed into ER2537 bacteria (New England Biolabs, Cat. No. 801-N). The transformed bacteria was transfected with VCSM13 helper phage (Stratagene, Cat. No. 200251) to obtain a phage, and a clone which binds to HER2-ECD-Fc was acquired using an immunotube, 5 to which HER2-ECD-Fc was immobilized. Among the colonies for each of the antibodies, the antibodies that bind to HER2-ECD-Fc were confirmed via ELISA assay. The colonies of the transformed bacteria were cultured at 37'C until their absorbance at 600 nm reached 0.5, and treated with IPTG at a final concentration of 1 mM, allowed to and expressed 10 antibodies in the form of Fab while culturing overnight at 30 C. After culturing 5 mL, cells were collected by centrifugation, suspended in 0.4 mL 1X TES (50 mM Tris, 1 mM EDTA, 20% (v/v) sucrose, pH 8.0), and treated at 4'C for 10 minutes. After adding 0.6 mL of 0.2X TES thereto, the resultant was treated at 4'C for 30 minutes, centrifuged and the supernatant was recovered. After washing the Costar 96-well half 15 area plate (Corning Inc., Cat. No. 3690), which was coated with HER2-ECD-Fc at a concentration of 1 [tg/mL, 3 times with TBS-T, it was blocked with TBS-T/SM (3% non-fat skim milk, 0.05% Triton X-100) at room temperature for 1 hour. The culture broth or periplasmic extract (Periplasm) for each colony was treated by diluting it at a 1:3 ratio using TBS-T/SM, and allowed to bind at room temperature for 1 hour. After 20 washing 3 times, anti-HA-HRP (Roche, Cat. No. 120-138-190-01) as a secondary antibody was diluted at a 1:5000 ratio, allowed to bind at room temperature for 1 hour, washed 3 times, and allowed to develop a color using TMB. Most colonies in the cell culture broth or periplasmic extract had absorbance of 0.2 or higher, and the sequences of the antibodies were analyzed regarding these 25 clones. The sequence analysis revealed that the colonies derived from a single hybridoma were shown to have the same sequences. The amino acid sequences of complementarity determining region (CDR) of the lEll antibody are summarized in Table 1 below. TABLE 1 30 Amino acid sequences of complementarity determining region (CDR) of the lEl1 antibody Light Chain Heavy Chain CDR1 LASQTIGTWLA SYTMS CDR2 ATSLAD YISNGGGSTYYPDTVKG CDR3 QQLYSTPWT HLGGTASFDY EXAMPLE 4: CONSTRUCTION AND PRODUCTION OF CHIMERIC 35 ANTIBODIES 19 Chimeric antibodies were constructed to prepare the antibodies of the present invention in a more druggable form. The variable region of the mouse antibodies, for which the nucleotide sequence analysis was completed, was amplified and bound to the human constant regions CK 5 and CH, and the heavy chain part was TA cloned by pcDNA3.3-TOPO (Invitrogen, Cat. No., K8300-01) vector, whereas the light chain part was TA cloned by pOptiVEC TOPO (Invitrogen, Cat. No., 12744-017) vector. The primers used for amplification are shown in Tables 2 and 3 below. The forward primers were inserted with a Clal restriction site, whereas the reverse primers were added with NheI restriction site for 10 the heavy chain and BsiWI restriction site for the light chain, respectively. Additionally, the forward primers in the variable region were added with a signal sequence so that the chimeric antibodies could be secreted in cell culture broth. The nucleotide sequences and amino acid sequences of Cx and CH used in the present invention are described in SEQ ID NOs: 11 through 14. 15 A PCR reaction (30 sec. at 95'C; 30 sec. at 58'C; and 30 sec. at 72'C) was repeatedly performed for 35 cycles using the primers and GoTaq DNA polymerase (Promega, Cat. No. M3005) described above. Each of the amplified PCR products of the variable regions and the constant regions, after being subjected to a 1% agarose gel electrophoresis, was purified using a Qiaquick gel extraction kit (QIAGEN, Cat. No. 20 28706). In order to connect the variable regions and the constant regions, the PCR products of the variable regions and the constant regions were mixed in an equal amount, and an overlap extension PCR was performed using the forward primers for the variable regions and the reverse primers for the constant regions to obtain gene products, and the products were purified in the same manner as described above. The 25 overlap extension PCR (30 sec. at 95'C; 30 sec. at 58'C; and 45 sec. at 72'C) was repeatedly performed for 35 cycles using the primers and was performed using the GoTaq DNA polymerase (Promega, Cat. No. M3005). The amplified gene products were TA cloned into pcDNA3.3-TOPO (Invitrogen, Cat. No., K8300-01) vector for the heavy chain part, and TA cloned into pOptiVEC-TOPO (Invitrogen, Cat. No., 12744 30 017) vector for the light chain part, according to the manufacturer's manual. TABLE2 Primers for amplification of variable regions Primers Sequence CCGATCGATATGGAGACAGACACACTCCTGCTATGGGTACTGCT LF-i GCTCTGGGTTCCAGGTTCCACGTGGGATATTCAGATG LR- 1 CGGCGTACGTTTCAGCTCCAGCTTGG CCGATCGATATGGAGACAGACACACTCCTGCTATGGGTACTGCT HF-i ,GCTCTGGGTTCCAGGTTCCACGTGGGAGGTGAAGCT 20 HR-1 CGGGCTAGCTGAGGAGACGGTGAC TABLE3 Primers for amplification of constant regions Primers Sequence Ck-F GGAGCTGAAACGTACGGTGGCTGCACC Ck-R CCGCTCGAGTTAACACTCTCCCCTGTTG CH-F CACCGTCTCCTCAGCTAGCACCAAGGGCCCATCG CH-R CCGCTCGAGTCATTTACCCGGGGACAGGGAG In the above Tables, the bold letters indicate the restriction sites for restriction 5 enzymes, whereas the underlined parts indicate signal sequences. The maps of the finally constructed pcDNA3.3-IgG Heavy vector and pOptiVEC-IgG Kappa vector are illustrated in FIG. 1. Then, the cloned vectors were transiently transfected into FreeStyleTM 293F (Invitrogen, Cat. No. R790-07) animal cells using polyethyleneimine (Polyscience 10 Inc., Cat. No. 23966), and chimeric antibodies were purified from the cell culture broth using Protein-A Ceramic HyperD F resin (PALL, Cat No. 20078-028). The purified chimeric antibodies were quantitated via BCA assay (Pierce, Cat. No. 23227), subjected to SDS-PAGE, and their concentration and purity were confirmed via Coomassie staining. 15 EXAMPLE 5: COMPARISON OF INHIBITORY EFFECTS OF DEVELOPED ANTIBODIES AGAINST THE GROWTH OF BREAST CANCER AND STOMACH CANCER In order to confirm the anticancer effects of the developed antibodies 20 according to their concentration, a cell viability assay was performed regarding cancer cell lines which overexpress HER2 such as, BT-474 (a breast cancer cell line), and NCI-N87 (a stomach cancer cell line). BT-474 (10,000 cells/well) and NCI-N87 (10,000 cells/well) at a volume of 70 [tL were aliquoted to a 96-well plate, and immobilized thereto while culturing for 24 hours. On the next day, 30 [tL of the 25 antibodies were added to the culturing cells. The final concentration of the treated antibodies was at maximum 20 [tg/mL per each antibody and sequentially diluted at a 1:4 ratio, and the assay was performed at 5 different concentrations. When treated in combination of trastuzumab, the ratio between the developed antibodies and trastuzumab was set at a 1:1 ratio (for example, in FIGS. 2A and 2B, when the amount 30 of administration was 1 [tg/mL, 1 [tg/mL of TRA and 1 [tg/mL of lEl1 were administered). After the treatment with the antibodies, BT-474 and NCI-N87 cells were cultured for 4 additional days, added with CCK-8 to a final concentration of 10%, and treated at 37'C for 3 hours. Then, the absorbance of the treated cells was 21 measured at 450 nm using Victor X-3. The absorbance of the cells not treated with the antibodies was set at 100%, and their relative viability was calculated (FIGS. 2A and 2B). The developed lEl1 antibody showed an inhibitory effect against the 5 proliferation of NCI-N87 (FIG. 2A) and BT-474 (FIG. 2B) cell lines, which were responsive to trastuzumab. Furthermore, the combined treatment of lEl1 antibody and trastuzumab showed a higher inhibitory activity against cancer cell proliferation than trastuzumab treatment alone, regarding the NCI-N87 and BT-474 cell lines. Interestingly, the combined treatment of lEl1 antibody and trastuzumab showed a 10 higher inhibitory activity against cancer cell proliferation than the combined treatment of trastuzumab and pertuzumab, regarding the NCI-N87 cell line (FIG. 2A). EXAMPLE 6: CONFIRMATION OF SYNERGISTIC EFFECT OF DEVELOPED ANTIBODIES IN COMBINATION TREATMENT WITH 15 TRASTUZUMAB In order to confirm whether the anticancer effect of the combined treatment of the developed 1E 11 antibody and trastuzumab in stomach cancer was synergistic effect, NCI-N87 cells were treated with lEl1 antibody or trastuzumab alone or in combination thereof the anticancer effects were analyzed (FIG. 2A). The anticancer 20 effect according to concentration was analyzed via CalcuSyn program (Biosoft) using Chou & Talalay method (Chou et al., Adv. Enzyme. Regul. 22:27-55(1984)) which analyzes the effect of combined administration of at least two drugs (Table 4). When two drugs are administered in combination they either become agonistic, additive, or synergistic. The mutual interactions of drugs can be analyzed using Chou & Talalay 25 method in terms of combination index (CI). The CI value of 1 or greater indicates an agonistic effect, while CI values of 1, and 1 or less indicate an additive effect, and a synergistic effect, respectively. TABLE 4 1E 11 + Trastuzumab C.I. r ED50 ED75 ED90 0.0315 0.0459 0.0751 0.95921 In the above Table, ED50, ED75 and ED90 indicate the effective doses, which 30 show effects in 50%, 75% and 90% populations, respectively. 'r' indicates a linear correlation coefficient of a median-effect plot. As can be seen in FIG. 2A and Table 4, the CI value of the two drugs of trastuzumab and 1E 11 clones at the time of their combined treatment was below 0.1, and thus the two antibodies were confirmed to have a synergistic effect when 35 administered in combination. 22 EXAMPLE 7: COMPARISON OF EPITOPES BETWEEN THE DEVELOPED ANTIBODIES AND TRASTUZUMAB Trastuzumab, the antibody to HER2, is known to bind to domain-4 among the 5 four domains of the HER2 ECD. In order to confirm whether the epitopes on HER2 of the developed antibodies overlap with the those of trastuzumab, an epitope binning was performed via surface plasmon resonance (SPR) using Biacore 3000 (GE Healthcare). About 1,000 RU (response unit) of trastuzumab was immobilized to a CM5 sensor chip (GE Healthcare, Cat. No. BR-1000-12) via an amine coupling 10 method using ECD/NHS. HER2-ECD-His protein at a concentration of 320 nM was allowed to bind to the sensor chip, to which the trastuzumab was immobilized, using HBS-P buffer (10 mM HEPES, 150 mM NaCl, 1 mM EDTA, 0.005% Tween-20, pH 7.4) for 4 minutes, and only the buffer was flowed thereonto for 5 minutes thereafter to stabilize the binding between trastuzumab and HER2-ECD. Then, the secondary 15 antibodies at a concentration of 1 [tg/mL were allowed to bind thereto for 4 minutes, and the buffer was allowed to flow thereonto. In all experiments, the flow rate was set at 50 tL/min. If the secondarily bound antibodies further bind to the HER2-ECD protein, to which trastuzumab was bound, they are antibodies that do not share the common epitope with trastuzumab. 20 As can be seen in FIG. 3A, hIgG, which was used as a secondary antibody, does not bind to HER2 and thus there was no additional binding, and since trastuzumab has the same epitope it did not bind further. In contrast, the lEl1 antibody was additionally bound to HER2-ECD, which was bound to trastuzumab, and thus it was confirmed to have an epitope which is different from that of trastuzumab. 25 In order to confirm the domain region to which the 1E 11 clones bind, the four sub-domains (domains 1-4) which constitute the extracellular domain of HER2 protein were individually produced using animal cells, to which the hinge region and the Fc region of human IgG1 were bound, and purified using Protein-A. The binding of the lEl1 clones, trastuzumab, pertuzumab was confirmed via ELISA assay regarding the 30 thus-produced recombinant protein. As can be seen in FIG. 3B, the lEl1 clones were shown to bind to the sub-domain 4, as in the case with trastuzumab. From the foregoing results, it was confirmed that 1E 11 clones bind to the sub domain 4 of ECD of the HER2 protein but they bind to an epitope which is different from that of trastuzumab (FIG. 3). 35 EXAMPLE 8: SPECIFICITY OF DEVELOPED ANTIBODY TO HER 2 Whether the developed 1E 11 antibodies bind specifically to HER2 among the ErbB family proteins, to which HER2 belongs, and whether they bind to HER2 of species other than humans were confirmed via ELISA assay. In order to confirm 40 whether the developed lEl1 antibodies bind specifically to HER2 among the ErbB family proteins, the extracellular domains of EGFR, HER2, HER3 and HER4, which belong to the ErbB family, were examined via ELISA assay. The extracellular 23 domains of EGFR (EGFR-ECD-Fc) were produced in the same manner as in HER2 ECD-Fc, and HER3 (R&D Systems, #348-RB-050) and HER4 (R&D Systems, #113 1 ER-050) were purchased. In order to confirm whether the developed antibodies exhibit interspecific cross-reactions to HER2 proteins of different species, HER2 5 extracellular domains of humans, a rhesus monkey, a cynomolgus monkey, a mouse, and a rat were used and confirmed via ELISA assay. The extracellular domain of a cynomolgus monkey was produced in the same manner as in human HER2-ECD-Fc, and the HER2 extracellular domain of a rhesus monkey (Sino Biological Inc., #90020 K08H), the HER2 extracellular domain of a mouse (Sino Biological Inc., #50714 10 M08H), and the HER2 extracellular domain of a rat (Sino Biological Inc., #80079 R08H) were purchased. As can be seen in FIGS. 4A and 4B, it was confirmed that the developed 1E 11 antibodies specifically bind to HER2 among the human ErbB family proteins, and have interspecific cross-reactions to HER2 proteins of a rhesus monkey and a cynomolgus 15 monkey. EXAMPLE 9: APOPTOSIS ANALYSIS OF HER2 ANTIBODIES We analyzed apoptosis induction abilities of HER2 antibodies to elucidate an underlying molecular mechanism of anticancer effects of lEll antibody co 20 administered with trastuzumab. To investigate apoptosis induction abilities, NCI-N87 and BT-474 cells were treated with 10 [tg/mL of lEl1 antibody, trastuzumab or its combination for 48 hr (10 [tg/mL of 1E 11 and 10 [tg/mL of trastuzumab for combined administration). After the antibody treatment, cells were detached with trypsin and 500,000 cells were analyzed using ApoScreen Annexin V Apoptosis kit 25 (SouthernBiotech, #10010-02) by a flow cytometry analysis (Cytomics FC500 Beckman Coulter Inc.) (Figs. 5a and 5b). To measure activities of caspase-3 and caspase-7 playing a crucial role in apoptosis, anticancer efficacies of lEll antibody, trastuzumab or combination thereof were analyzed over treatment time. NCI-N87 cells were treated with 10 [tg/mL of 30 antibodies. After 24 hr and 48 hr of the treatment, cell viability assay was performed using Caspase-Glo (Promega, #G7571) (Fig. 5c). It was shown that the cell viability was sharply decreased after 24 hr of the treatment. Based on such results, the activities of caspase-3/7 were measured after 24 hr of the treatment. NCI-N87 cells were treated with 10 [tg/mL of antibodies for 24 hours. Caspase-Glo 3/7 Assay (Promega, #G809) 35 was used to measure caspase-3/7 activity (Fig. 5d). As represented in Figs. 5a and 5b, lEl1 antibody alone was shown to exert apoptotic activity to HER2-overexpressing stomach cancer (NCI-N87 cells) and breast cancer (BT-474 cells), which are unlike trastuzumab. The apoptotic activity of lEl1 antibody was further increased with combined treatment with trastuzumab. The 40 increased apoptotic activity of the combined treatment with 1E 11 and trastuzumab was analyzed to be due to increase in caspase-3/7 activity playing a crucial role in apoptosis (Fig. 5d). 24 EXAMPLE 10: HER2 CELL SIGNALING INHIBITION BY ANTIBODIES To elucidate the anticancer mechanism of lEll in combination with trastuzumab against HER2-overexpressing stomach cancer and breast cancer, we 5 analyzed HER2 signaling activities in cells. NCI-N87 cells were treated with 10 [ig/mL of antibodies for 24 hours. Then cells were lysed with cell lysis solution [50 mM Tris, pH 7.4, 150 mM NaCl, 1% NP-40, 0.1% sodium dodecyl sulfate, 1 mM NaF, 1 mM Na3VO4, 1 mM PMSF and protease inhibitor cocktail (Sigma)] for obtaining a cell lysate. The cell lysate underwent the Western blot analysis. HER2 (#4290), pHER2 10 (#2243), pHER3 (#4791), EGFR (#4267), pEGFR (#3777), AKT (#4691), pAKT (#4060), ERK (#4695), and pERK (#4370) antibodies were purchased from Cell Signaling Technology. HER3 (sc-285) antibody was purchased from Santa Cruz Biotechnology and GAPDH (AbC-1001) antibody as a loading control was purchased from AbClon. The horseradish peroxidase-conjugated anti-mouse (AbC-5001) and 15 anti-rat (AbC-5003) antibodies were also purchased from AbClon. The bands were visualized using AbSignal (AbClon, AbC-3001). We further examined whether the combined treatment of 1E 11 and trastuzumab inhibits heterodimerization between HER2 and EGFR or HER3 as another ErbB family proteins. NCI-N87 cells were treated with EGF for induction of 20 heterodimerization between HER2 and EGFR, and treated with HRG for induction of heterodimerization between HER2 and HER3. NCI-N87 cells were aliquoted in a cell medium supplemented with 0.1% FBR and cultured for 24 hr. Then, the cells were treated with 10 [tg/mL of antibodies for 1 hr, and then with 200 ng/mL of EGF (R&D Systems, #236-EG-200) or HRG (R&D Systems, #377-HB/CF). Three-day later, the 25 cell viability was tested. As shown in Fig. 6a, the combined treatment of lEll and trastuzumab contributes to decrease in level of the HER2 protein. Upon decrease in level of the HER2 protein, the phosphorylated HER2 protein was also decreased. We observed reduced phosphorylated HER3 and EGFR level without total protein level change. 30 Such results demonstrate that the combined treatment of lEll and trastuzumab is able to control activities of HER2, HER3 and EGFR. By such activity controls, activities of AKT and ERK, well-known HER2 downstream factors, were also altered without total protein level change. It was shown that the combined treatment of 1E 11 and trastuzumab resulted in 35 reduction of cell proliferation by heterodimerization between HER2 and EGFR (or HER3) (Fig. 6b). NCI-N87 cell proliferation by EGF capable of inducing heterodimerization between HER2 and EGFR, and HRG capable of inducing heterodimerization between HER2 and HER3, was reduced by the combined treatment of lEll and trastuzumab to a similar level to pertuzumab known to inhibit HER2 40 binding to other receptors. These results address that cell signaling through heterodimerization between HER2 and EGFR (or HER3) was suppressed by the combined treatment of lEll and 25 trastuzumab. EXAMPLE 11: ANTICANCER EFFICACIES OF ANTIBODIES IN ANIMAL MODELS 5 The anticancer efficacies of lEll antibody were evaluated using animal models. Athymic nude female mice (Daehan Biolink, Korea) were injected subcutaneously with 5 x 106 of NCI-N87 cells to prepare xenograft model. Tumors were allowed to grow about 200 mm 3 in size, and mice were then randomized into four groups. Animals of the four groups received twice weekly intraperitoneal 10 administration of 10 mg/kg of palivizumab (as isotype control of trastuzumab (MedImmune LLC.)), lEl1, trastuzumab, and combination of lEl1 and trastuzumab, respectively. For combined administration, each antibody was administered in a doge of 10 mg/kg. Tumor volumes were measured over time. On day 22, the animals were sacrificed and the tumors were isolated. Tumor volumes were calculated using the 15 formula (L*W*W)/2, where "L" represents the larger tumor diameter and "W" represents the smallest tumor diameter. The isolated tumors were weighed and prepared for immunohistochemistry analyses. Tumor xenograft tissues were processed as formalin-fixed and paraffin-embedded specimen sections. These were examined by hematoxylin (DAKO, #CS700) and eosin (DAKO, #CS701) (H&E) staining and 20 HER2 protein staining using HER2 antibody (Cell Signaling Technology, #4290). lEl1 alone inhibited tumor growth to an extent similar to trastuzumab (Fig. 7a). lEl1 showed dramatically increased antitumor activity in combination with trastuzumab compared with each single antibody treatment. The antitumor activity was also confirmed by analyzing tumor mass extracted after experiments (Fig. 7b). The 25 reduction of HER2-expressing cells by the combined treatment of lEl1 and trastuzumab was observed in immunohistochemistry staining (Fig. 7c), which is compatible with results of the Western blotting (Fig. 6a). These results indicate that lEl1 in combination with trastuzumab dramatically inhibits tumor growth compared with single antibody treatment, which is due to suppression of expression of the HER2 30 protein. EXAMPLE 12: DEVELOPMENT OF HUMANIZED ANTIBODIES AND CONFIRMATION OF THEIR EFFECTS The humanized antibodies of the chimeric lEl1 antibodies developed in 35 Example 4 were developed using a CDR grafting method. Regarding the human antibodies to receive the CDR of the developed antibodies, V and J genes of human germline antibody genes with high nucleotide sequence based-homology were selected using IMGT/V-QUEST (Brochet, X. et al., Nucl Acids Res. 36:503-508(2008)). As a V gene and a J gene of a heavy chain, IGHV3-48*03 gene and IGHJ4*01 gene were 40 selected, respectively, and their sequence homology was 85.07% and 87.23%, respectively. Additionally, as a V gene and a J gene of a light chain, IGKV1-39*01 gene and IGKJ1*01 gene were selected, respectively, and their sequence homology 26 was 81.36% and 81.08%, respectively. Considering a report that grafting of CDR only decreases affinity, H49 based on the Kabat numbering of the heavy chain corresponding to the Vernier zone that can affect the entire structure of an antibody was replaced with alanine instead of serine, which is on the human germline gene. 5 The developed humanized antibody hzlEl1 was produced in the form of IgG using FreeStyleTM 293F cell line. The amino acid sequences of the heavy chain variable region and the light chain variable region of the developed hzlEl1 are described in SEQ ID NOS: 24 and 26, respectively. The affinity of hzlE 11, the developed humanized antibody of 1E 11, for HER2 10 was measured via surface plasmon resonance (SPR) assay. All the experiments were performed using Biacore 3000. First, the goat antibodies to human IgG were immobilized at a concentration of 1000 RU to a CM5 sensor chip via an amine coupling method. Trastuzumab, pertuzumab, and hzlEl1 were respectively diluted to 2.84 pM, 5.68 pM, and 7.1 pM using a HBS-P buffer. Before binding to HER2 15 ECD-His protein, each antibody was bound at a rate of 50 tL/min for 180 seconds, and allowed the buffer to flow thereonto for stabilization purpose. Then, HER2 ECD-His protein was allowed to bind at concentrations of 640 nM, 320 nM, 160 nM, 80 nM, 40 nM, 20 nM, and 0 nM for 4 minutes, and allowed the buffer to flow thereonto for 15 minutes. The sensor chip was recycled by allowing 10 mM Glycine 20 HCl (pH 1.5) buffer to flow thereonto. All the sensorgram data was analyzed via a 1:1 interaction model using BlAevaluation software. The affinities of antibodies are summarized in Table 5 below. The affinities of trastuzumab and pertuzumab were 1.94 nM and 1.89 nM, respectively, whereas the affinity of the developed antibody lEll was 16.0 nM. The affinity of the humanized antibody of lEll was 10.4 nM, 25 showing almost no difference from the existing E1 1 antibody. TABLE 5 Antibodies Ka (M-ls-1) Kd (s-1) KD (nM) Trastuzumab 3.9E+04 7.6E-05 1.94 Pertuzumab 3.6E+04 6.8E-05 1.89 lEll 3.OE+04 4.7E-04 16.0 hzlEll 4.9E+04 5.1E-04 10.4 The anticancer effect of hzlE 11, the developed humanized antibody of 1E11, was confirmed in human stomach cancer cell lines NCI-N87 and OE-19, which overexpress HER2 (FIG. 8). The single treatment of hzlEl1 in NCI-N87 cells 30 showed a decrease in cancer survival rate similar to that of trastuzumab treatment, whereas the combined treatment of hzlEl1 and trastuzumab showed a significantly higher decrease in cancer survival rate compared to the single treatment by either antibody (FIG. 8A). Additionally, the combined treatment of hzlEl1 and trastuzumab in OE-19, a different human stomach cancer cell line, showed a higher 35 decrease in cancer survival rate compared to the single treatment by either antibody (FIG. 8B). Additionally, the combined treatment of hzlEl1 and trastuzumab showed 27 a bit higher inhibitory effect than the combined treatment of 1Eli and trastuzumab (FIG. 2A) against the proliferation of cancer cells (FIG. 8A). The combined treatment of hzlEl1 and trastuzumab showed a higher inhibitory effect in NCI-N87 OE-19 cell lines than the combined treatment of trastuzumab and pertuzumab against 5 the proliferation of cancer cells. The above results indicate that the hzlE 11, the developed humanized antibody of lEl1, has an equal binding capacity and a bit improved anticancer effect as compared to the conventional 1E11. The anticancer effect of the combined treatment of the hzlE 11, the developed 10 humanized antibody of lEl1, along with trastuzumab was confirmed in a xenograft model using NCI-N87. The mice having a cancer formed via NCI-N87 transplantation were intraperitoneally injected twice a week with the developed antibody and an isotype control group of trastuzumab, hzlEl1, trastuzumab, and a combination of hzlEl1 and trastuzumab, respectively. The isotype control group and trastuzumab 15 were administered at a dose of 10 mg/kg. In the case of a combined treatment, hzlEl1 and trastuzumab were mixed at a 1:1 ratio, and administered at a dose of 1 mg/kg, 2.5 mg/kg, 5 mg/kg and 10 mg/kg based on each antibody. The combined treatment of hzlEl1 and trastuzumab showed a decrease of cancer growth in a dose dependent manner (FIG. 9). The anticancer effect observed with administration of 10 20 mg/kg of trastuzumab was also observed with administration of 1 mg/kg of hzlEl 1 or trastuzumab. The administration of hzlEl1 and trastuzumab in a dose of greater than 5 mg/kg was shown to not only inhibit the growth of cancer but also decrease the cancer already formed. 25 Example 13: CONFIRMATION OF BINDING REGION OF DEVELOPED ANTIBODIES In order to confirm the important region of the developed antibodies for binding to antigens, an alanine scanning assay which examines the binding capacity by changing the amino acids corresponding to CDR3 of the heavy chain and the light 30 chain to alanine was performed. Histidine (H), leucine (L), glycine (G), glycine (G), threonine (T) and serine (S) among the CDR3 region of the heavy chain which correspond to 95, 96, 97, 98, 99 and 100a according to the Kabat numbering, and glutamine (Q), glutamine (Q), leucine (L), tyrosine (Y), serine (S) and threonine (T) among the CDR3 region of the light chain which correspond to 89, 90, 91, 92, 93 and 35 94 according to the Kabat numbering, were changed to alanine using the QuikChange Site-directed Mutagenesis kit (Stratagene, #200518). Among the CDR3 of the heavy chain, A100 was excluded from the assay because the developed antibody has alanine. After expressing each modified antibody in bacteria, its expression was confirmed via a dot-blot after obtaining a periplasmic extract therefrom, and the binding capacity was 40 analyzed regarding the HER2-ECD via ELISA assay (see: FIG. 10). TABLE 6 Mutated sequence Mutated Binding capacity to Her2 28 position ECD (absorbance at 450nm) AQLYSTPWT Q89A 1.711 QALYSTPWT Q90A 1.705 QQAYSTPWT L91A 1.492 CDR-L3 QQLASTPWT Y92A 1.803 QQLYATPWT S93A 1.733 QQLYSAPWT T94A 1.628 ALGGTASFDY H95A 1.59 HAGGTASFDY L96A 1.66 HLAGTASFDY G97A 1.08 CDR-H3 HLGATASFDY G98A 0.051 HLGGAASFDY T99A 0.839 HLGGTAAFDY S100aA 1.597 Parent Antibody hzlEll 1.75 As can be seen in Table 6 and FIGS. 13A and 10B, the modified antibodies were expressed in a similar level, whereas G98A of the heavy chain showed a complete loss of its binding capacity, and G97A of the heavy chain showed a marked decrease in its binding capacity. The change in other regions did not show any 5 noticeable effect on the antigen-antibody binding. Example 14: IMPROVEMEENT OF AFFINITIES OF DEVELOPED ANTIBODIES In order to improve the affinities of the developed antibodies, a library with 10 randomized CDR3 of the light chain and the heavy chain was developed. F, D, and Y among the CDR3 of the heavy chain which correspond to F100b, D101, and Y102, the amino acid numbers according to the Kabat numbering, and P, W, and T among the CDR3 of the light chain which correspond to P95, W96, and T97 according to the Kabat numbering were excluded from the randomization because they are commonly 15 discovered amino acids in human antibodies. A phage antibody library with 20 randomized amino acids of CDR3 amino acids of the heavy chain and the light chain exclusive of the amino acids described in the above technology was developed (Phage display: a laboratory manual, Carlos Barbas III, et al., Cold Spring Harbor Laboratory Press). In particular, the primers used above relate to the region corresponding to 20 CDR3 of the heavy chain and the light chain, and were synthesized such that adenine (A), cytosine (C), guanine (G) and thymine (T) were mixed in an equal ratio to be inserted randomly into the first and second positions of the codon corresponding to the amino acid to be randomized, and guanine (G) or cytosine (C) were mixed in an equal ratio to be inserted into the third position. 29 In order to select the clones with improved affinities from the developed library, the HER2-ECD-His protein was biotinylated using the EZ-Link Sulfo-NHS LC-Biotinylation kit (Thermo Scientific, #21435), and used as antigens for selecting antibodies. The developed phage antibody library and biotin-HER2-ECD-His protein 5 were allowed to bind at room temperature for 2 hours, and the phages bound to the antigens were separated using 50 [tL of Dynabeads M-270 Streptavidin (Invitrogen, #653.06). The above selection process was performed 4 times, and the colonies that expressed antibodies that bind to HER2-ECD among the thus-selected colonies were selected via ELISA assay using periplasmic extracts, and the sequences of the 10 antibodies expressed in the selected colonies were confirmed via nucleotide analysis. The amino acid sequences of CDR3 of the heavy chain and the light chain of the antibodies that bind to HER2-ECD are summarized in Tables 7 and 8 below. The number 1 in each Table represents the amino acid sequence of CDR3 of the heavy chain and the light chain of hz 1 E11. 15 TABLE 7 CDRH3 sequences of mutants selected from the process of improving affinity 1 HLGGTASFDY 14 HLGGMSSFDY 27 HWGGTASFDY 40 PLGGTASFDY 2 AFGGTASFDY 15 HLGGMTSFDY 28 HYGGTASFDY 41 QLAGTASFDY 3 DLGGTASFDY 16 HLGGSSSFDY 29 MNGGTASFDY 42 SFGGTASFDY 4 FWGGTASFDY 17 HLGGTACFDY 30 NFGGTASFDY 43 SHGGTASFDY 5 HCGGTASFDY 18 HLGGTGAFDY 31 NHGGMASFDY 44 SLGGTASFDY 6 HFGGTASFDY 19 HLGGTGSFDY 32 NHGGTASFDY 45 SMGGTASFDY 7 HHGGTASFDY 20 HLGGTSTFDY 33 NIGGTASFDY 46 SNGGTASFDY 8 HIGGTASFDY 21 HLGGTTSFDY 34 NLGGTASFDY 47 SWGGTASFDY 9 HLCSTASFDY 22 HLGSTASFDY 35 NMGGTASFDY 48 SYGGTASFDY 10 HLCVTASFDY 23 HLYRTASFDY 36 NNGGTASFDY 49 YYGGTASFDY 11 HLGGAASFDY 24 HMGGTASFDY 37 NWGGTASFDY 12 HLGGLPSFDY 25 HRGGTASFDY 38 NYGGAASFDY 13 HLGGMASFDY 26 HVGGTASFDY 39 NYGGTASFDY TABLE 8 CDRL3 sequences of mutants selected from the process of improving affinity 1 QQLYSTPWT 41 QQLAYEPWT 81 QQMAFVPWT 121 QQMVRTPWT 2 DQLYGTPWT 42 QQLAYSPWT 82 QQMAFYPWT 122 QQMVRVPWT 3 DQMYSTPWT 43 QQLAYTPWT 83 QQMAGFPWT 123 QQMVSIPWT 4 HQLAFTPWT 44 QQLAYVPWT 84 QQMASVPWT 124 QQMYGTPWT 5 LQHNEFPWT 45 QQLGFAPWT 85 QQMAYGPWT 125 QQMYKTPWT 6 QDMSRTPWT 46 QQLGFIPWT 86 QQMAYSPWT 126 QQMYRTPWT 7 QELSTTPWT 47 QQLGFSPWT 87 QQMAYTPWT 127 QQNAFEPWT 8 QEMMRTPWT 48 QQLGFVPWT 88 QQMDFTPWT 128 QQNAFGPWT 9 QNLAYSPWT 49 QQLGYAPWT 89 QQMEHTPWT 129 QQNAFIPWT 30 10 QNMYGTPWT 50 QQLGYSPWT 90 QQMFAIPWT 130 QQNAFSPWT 11 QQAAFSPWT 51 QQLHSTPWT 91 QQMFGSPWT 131 QQNAFTPWT 12 QQAAYSPWT 52 QQLKNTPWT 92 QQMFRTPWT 132 QQNAFVPWT 13 QQAAYVPWT 53 QQLMRKPWT 93 QQMFSTPWT 133 QQNAYAPWT 14 QQCTSDPWT 54 QQLRASPWT 94 QQMFSVPWT 134 QQNAYGPWT 15 QQHDVGPWT 55 QQLRNLPWT 95 QQMGFSPWT 135 QQNAYNPWT 16 QQIAFGPWT 56 QQLRNSPWT 96 QQMGYAPWT 136 QQNAYSPWT 17 QQIAFNPWT 57 QQLRNVPWT 97 QQMGYSPWT 137 QQNFIAPWT 18 QQIAFSPWT 58 QQLRSAPWT 98 QQMHIFPWT 138 QQNMIVPWT 19 QQIAFTPWT 59 QQLRSSPWT 99 QQMMAVPWT 139 QQNRISPWT 20 QQIAFVPWT 60 QQLRSVPWT 100 QQMMKSPWT 140 QQNRIWPWT 21 QQIAKTPWT 61 QQLRVIPWT 101 QQMMRTPWT 141 QQNRVIPWT 22 QQIAYSPWT 62 QQLSFTPWT 102 QQMMRVPWT 142 QQNRVVPWT 23 QQIAYTPWT 63 QQLSFVPWT 103 QQMRKIPWT 143 QQNSYSPWT 24 QQIAYVPWT 64 QQLSKTPWT 104 QQMRNVPWT 144 QQNVIVPWT 25 QQIFSVPWT 65 QQLSRAPWT 105 QQMRRVPWT 145 QQNVNVPWT 26 QQIGFSPWT 66 QQLSRSPWT 106 QQMRSTPWT 146 QQNYKLPWT 27 QQIGWTPWT 67 QQLSVTPWT 107 QQMSFSPWT 147 QQSAFVPWT 28 QQIMTLPWT 68 QQLSYAPWT 108 QQMSHSPWT 148 QQSAYAPWT 29 QQIREIPWT 69 QQLSYSPWT 109 QQMSKIPWT 149 QQSAYIPWT 30 QQISFMPWT 70 QQLVRIPWT 110 QQMSRVPWT 150 QQSEACPWT 31 QQISFSPWT 71 QQLVRNPWT 111 QQMSYAPWT 151 QQSFNTPWT 32 QQIYITPWT 72 QQLVRTPWT 112 QQMSYGPWT 152 QQSKTVPWT 33 QQKAYAPWT 73 QQLVRVPWT 113 QQMSYIPWT 153 QQTAFGPWT 34 QQKKGIPWT 74 QQLYSSPWT 114 QQMSYSPWT 154 QQTAFSPWT 35 QQKMGNPWT 75 QQMAFAPWT 115 QQMSYTPWT 155 QQTAYAPWT 36 QQKSVAPWT 76 QQMAFGPWT 116 QQMSYVPWT 156 QQTAYSPWT 37 QQLAFAPWT 77 QQMAFIPWT 117 QQMTRVPWT 157 QQTRRTPWT 38 QQLAFMPWT 78 QQMAFNPWT 118 QQMVIIPWT 158 QQTSFAPWT 39 QQLAFSPWT 79 QQMAFSPWT 119 QQMVREPWT 159 QQVAYSPWT 40 QQLAFVPWT 80 QQMAFTPWT 120 QQMVRSPWT 160 QQVFAIPWT In order to select clones with improved Koff among the selected clones, the clones were analyzed via Biacore 3000 (GE Healthcare). The HER2-ECD-His protein was immobilized to a CM5 sensor chip via an amine coupling method using ECD/NHS. After expressing the antibody from each clone using IPTG, a periplasmic 5 extract was obtained therefrom, and allowed to bind to HER2-ECD-His. The Koff value for each antibody was analyzed via BlAevaluation software. Based on the above, the antibodies with improved Koff value were selected (see: Table 9a). Table 9a disclose the representative examples of the clones showing similar or improved Koff values compared to the hzlE 11 parent antibody, among the clones developed by 10 the present inventors. TABLE 9a 31 hzlEl1 Mutation- Degree of Clones introduced koff reduction LCDR3 HCDR3 chain (Fold) hzlEll QQLYSTPWT HLGGTASFDY - 1.13E-03 1.0 M3-L-Al-3 1A12 QQNAYAPWT HLGGTASFDY L 3.72E-05 30.4 (hzlEli-133) M3-L-Al-3 1F11 QQTAFSPWT HLGGTASFDY L 1.17E-04 9.7 (hzlEl1-154) M1-L-A1-3-1C3 DQMYSTPWT HLGGTASFDY L 1.52E-04 7.4 (hzlEli-3) M3-H-Al1-2 1Bl2- QQLYSTPWT NYGGTASFDY H 2.12E-04 5.3 1B12 M1-H-Al-2-1B5 QQLYSTPWT HFGGTASFDY H 4.53E-04 2.5 M3-H-A1-1- QQLYSTPWT SWGGTASFDY H 5.67E-04 2.0 'Cil M3-H-A1-1- QQLYSTPWT SYGGTASFDY H 1.16E-03 1.0 LAlO M3-LH-A1-1- QQNFIAPWT NYGGTASFDY LH 1.66E-03 0.7 M3-LH-A3-3 2B 1 QQLVRNPWT NFGGTASFDY LH 1.65E-04 6.5 M3-L-A3-4-2E8 QQIAYVPWT HLGGTASFDY L 1.80E-04 5.9 M1-LH-A3-3 lA3 QQLVRTPWT NYGGTASFDY LH 1.84E-04 5.8 1A6 M3-H-A3-3-2A7QQLSYSTPWT NFGGTASFDY H 2.26E-04 4.7 M3-LH-A3-3 2FL 3 1 QQNAYNPWT HLGGTASFDY L 2.45E-04 4.4 2F1 2A5 QQMFSTPWT HWGGTASFDY LH 2.98E-04 3.6 M3-H-A3-3-2D8 QQLYSTPWT HWGGTASFDY H 3.30E-04 3.2 M3-LH-Ai-2- QQLVRIPWT NLGGTASFDY LH 3.31E-04 3.2 2F4 M3-L-Al-3-2C2 QQLGFIPWT HLGGTASFDY L 5.26E-04 2.0 M3-H-A3-1-2F3 QQLYSTPWT NLGGTASFDY H 7.70E-04 1.4 M3-H-A2-1-1F2 QQLYSTPWT SNGGTASFDY H I1.27E-03 0.8 32 As can be seen in Table 9a, various CDRH3s represented by general formula 1 and CDRL3s represented by general formula 2 of the present invention show similar or improved Koff values compared to CDRH3 and CDRL3 of the parent antibody, hzlEli. 5 Among the randomized CDR3 sequence of the light chain, experiments were performed using hzlEl1-3, hzlEl1-133 and hzlEl1-154. The heavy chain variable regions of hzlEll-3, hzlEll-133 and hzlEll-154 were the same as that of hzlEll, and the amino acid sequence of the light chain variable regions are described in SEQ ID NOS: 247, 249 and 251, respectively. 10 In order to confirm the increase in affinities of the selected 3 kinds of antibodies, the antibodies were produced in the form of IgG. The goat anti-human IgG (Invitrogen, #H10500) at a concentration of 2000 RU was immobilized to a CM5 sensor chip via ECD/NHS method. Then, the antibodies were allowed to bind at a rate of 50 tL/min for 5 minutes, and allowed the buffer to flow thereonto for 5 minutes 15 for stabilization purpose. The concentrations of the antibodies used for binding of the antibodies were 0.4 [tg/mL for Trastuzumab (TRA), 0.8 [tg/mL for pertuzumab (PER), and 1 [tg/mL for hz lE 11 and the selected antibodies. After stabilizing the antibodies, the HER2-ECD-His protein at concentrations of 640 nM, 320 nM, 160 nM, 80 nM, 40 nM, 20 nM, and 0 nM was allowed to bind at a rate of 50 tL/min for 4 minutes, and 20 allowed the buffer to flow thereonto for 15 minutes to separate. After analyzing each of the concentrations, they were recycled using 10 mM Glycine (pH 1.5) and performed the subsequent assays. The affinities of the antibodies were analyzed via BlAevaluation software. The results of analysis are summarized in Table 9b. TABLE 9b Ka KD Antibodies kd (1/s) Rmax (1/Ms) (M) hzlEll 3.60E+04 8.30E-04 61 2.30E-08 hzlEll-3 3.80E+04 2.OOE-04 64 5.20E-09 hzlEll-133 6.40E+04 9.90E-05 68 1.50E-09 hzlEll-154 8.60E+04 9.90E-05 65 1.10E-09 TRA 4.90E+04 1.50E-04 43 3.OOE-09 PER 3.80E+04 1.20E-04 56 3.30E-09 25 In Table 9b above, ka, kd Rmax and KD respectively indicate association rate constant, dissociation rate constant, maximum binding capacity, and equilibrium dissociation constant. 33 As can be seen in Table 9b, hzlE11-133 and hzlE11-154 showed an 8.4-fold decrease in Koff value, i.e., kd values, compared to that of hzlEll, whereas they showed a bit increase in kon value, i.e., ka value. Conclusively, with respect to final affinity, hzlEll-133 showed 1.5 nM and hzlEll-154 showed 1.1 nM, which were a 5 15-fold improvement and a 20-fold improvement compared to that of hzlE11. Example 15: CONFIRMATION OF ANTICANCER EFFECTS OF ANTIBODIES WITH IMPROVED AFFINITIES The anticancer effects of the antibodies with improved affinities were 10 confirmed regarding HER2-overexpressing stomach cancer and breast cancer. Cancer cell survival rates when NCI-N87 and OE-19, HER2-overexpressing stomach cancer cell lines, BT-474, a HER2-overexpressing breast cancer cell line treated with single treatment by each antibody alone or a combined treatment along with of trastuzumab, according to concentration, were analyzed 15 As can be seen in FIGS. 11A to 11F, the hzlEl1-3, hzlEl1-133, and hzlEl1 154 antibodies with improved affinities showed improved effects in single treatment and combined treatment compared to that of hz 1 E11. Having described a preferred embodiment of the present invention, it is to be 20 understood that variants and modifications thereof falling within the spirit of the invention may become apparent to those skilled in this art, and the scope of this invention is to be determined by appended claims and their equivalents. 25 34

Claims (27)

1. An antibody to human epidermal growth factor receptor 2 (HER2) or antigen binding fragment thereof, comprising: (a) a heavy chain variable region comprising a complementarity determining 5 region (CDR) H1 of SEQ ID NO:1, CDRH2 of SEQ ID NO:2 and CDRH3 represented by the following formula 1; and (b) a light chain variable region: X 1 -X 2 -X 3 -X 4 -X 5 -X 6 -X 7 -Phe-Asp-Tyr (1) wherein Xi represents His, Asn, Ser or Ala; X 2 represents Leu, Phe, Tyr, His, Met, 10 Trp, Asn, Ile or Ala; X 3 represents Gly or Cys; X 4 represents Gly or Ser; X 5 represents Thr, Met or Ala; X 6 represents Ala, Ser, Gly or Thr; and X 7 represents Ser, Ala, Cys or Thr.

2. The antibody or antigen-binding fragment thereof according to claim 1, wherein 15 X 2 represents Leu, Phe or Tyr.

3. The antibody or antigen-binding fragment thereof according to claim 1, wherein X 3 represents Gly. 20

4. The antibody or antigen-binding fragment thereof according to claim 1, wherein X 4 represents Gly.

5. The antibody or antigen-binding fragment thereof according to claim 1, wherein Xi represents His, Asn or Ser; X 2 represents Leu, Phe or Tyr; X 3 represents Gly; X 4 25 represents Gly; X 5 represents Thr, Met or Ala; X 6 represents Ala, Ser, Gly or Thr; and X 7 represents Ser, Ala, Cys or Thr.

6. The antibody or antigen-binding fragment thereof according to claim 5, wherein Xi represents His, Asn or Ser; X 2 represents Leu, Phe or Tyr; X 3 represents Gly; X 4 30 represents Gly; X 5 represents Thr; X 6 represents Ala; and X 7 represents Ser.

7. The antibody or antigen-binding fragment thereof according to claim 1, wherein the CDRH3 comprises the amino acid sequence selected from the group of SEQ ID NOs:3, 27-28, 32 and 39-86. 35

8. The antibody or antigen-binding fragment thereof according to claim 1, wherein the CDRH3 comprises the amino acid sequence of SEQ ID NOs:3, 43, 64, 67, 71, 76, 83, 84 or 85. 40

9. The antibody or antigen-binding fragment thereof according to claim 8, wherein the CDRH3 comprises the amino acid sequence of SEQ ID NO:3. 35

10. The antibody or antigen-binding fragment thereof according to claim 1, wherein the light chain variable region comprises CDRL1 of SEQ ID NO:4, CDRL2 of SEQ ID NO:5 and CDRL3 represented by the following formula 2: Y1-Y 2 -Y 3 -Y 4 -Y 5 -Y-Pro-Trp-Thr (2) 5 wherein Yi represents Gln, Asp or Ala; Y 2 represents Gln, Asn, Glu or Ala; Y 3 represents Leu, Met, Asn, Ile, Ser, Thr, Ala or Lys; Y 4 represents Tyr, Ala, Ser, Arg, Val, Gly, Met or Phe; Y 5 represents Ser, Phe, Tyr, Arg, Ile, Gly, Lys, Asn, Val or Ala; and Y 6 represents Thr, Ser, Val, Ile, Ala, Gly, Asn, Glu, Phe or Leu. 10

11. The antibody or antigen-binding fragment thereof according to claim 10, wherein Y 2 represents Gln.

12. The antibody or antigen-binding fragment thereof according to claim 10, wherein Y 3 represents Leu, Met, Asn, Ile, Ser or Thr. 15

13. The antibody or antigen-binding fragment thereof according to claim 10, wherein Y 5 represents Ser, Phe, Tyr, Arg or Ile.

14. The antibody or antigen-binding fragment thereof according to claim 10, wherein 20 Y 6 represents Thr, Ser, Val, Ile, Ala, Gly or Asn.

15. The antibody or antigen-binding fragment thereof according to claim 10, wherein Yi represents Gln or Asp; Y 2 represents Gln; Y 3 represents Leu, Met, Asn, Ile, Ser or Thr; Y 4 represents Tyr, Ala, Ser, Arg, Val, Gly, Met or Phe; Y 5 represents Ser, Phe, 25 Tyr, Arg or Ile; and Y 6 represents Thr, Ser, Val, Ile, Ala, Gly or Asn.

16. The antibody or antigen-binding fragment thereof according to claim 10, wherein the CDRL3 comprises the amino acid sequence of SEQ ID NOs:6, 33-38 or 87-245. 30

17. The antibody or antigen-binding fragment thereof according to claim 16, wherein the CDRL3 comprises the amino acid sequence of SEQ ID NOs:6, 88, 109, 131, 155, 156, 157, 178, 218, 220, 222 or239.

18. The antibody or antigen-binding fragment thereof according to claim 17, wherein 35 the CDRL3 comprises the amino acid sequence of SEQ ID NOs:6, 88, 218 or 239.

19. The antibody or antigen-binding fragment thereof according to claim 9, wherein the heavy chain variable region comprises the amino acid sequence of SEQ ID NOs:8 or 24. 40

20. The antibody or antigen-binding fragment thereof according to claim 18, wherein the light chain variable region comprises the amino acid sequence of SEQ ID NOs: 10, 36 26, 247, 249 or 251.

21. A pharmaceutical composition for preventing or treating a cancer, comprising: (a) a pharmaceutically effective amount of the antibody to HER2 or antigen-binding 5 fragment thereof according to any one of claims 1-20; and (b) a pharmaceutically acceptable carrier.

22. The pharmaceutical composition according to claim 21, wherein the composition further comprises trastuzumab. 10

23. The pharmaceutical composition according to claim 21, wherein the cancer is breast cancer, ovarian cancer, stomach cancer, lung cancer, liver cancer, bronchus cancer, nasopharyngeal cancer, laryngeal cancer, pancreatic cancer, bladder cancer, colorectal cancer, colon cancer, cervical cancer, brain cancer, prostate cancer, bone 15 cancer, head and neck cancer, skin cancer, thyroid cancer, parathyroid cancer or ureteral cancer.

24. The pharmaceutical composition according to claim 23, wherein the cancer is breast cancer or stomach cancer. 20

25. A pharmaceutical composition for inducing apoptosis, comprising: (a) a pharmaceutically effective amount of the antibody to HER2 or antigen-binding fragment thereof according to any one of claims 1-20; and (b) a pharmaceutically acceptable carrier. 25

26. The pharmaceutical composition according to claim 25, wherein the pharmaceutical composition induces apoptosis for prevention or treatment of a hyperproliferative disease; wherein the hyperproliferative disease is cancer, hyperplasia, keloid, Cushing syndrome, primary aldosteronism, erythroplakia, 30 polycythemia vera, leukoplakia, hyperplastic scar, lichen planus, lentiginosis, arteriosclerosis , atherosclerosis, restenosis or stenosis.

27. A kit for diagnosing a cancer comprising the antibody to HER2 or antigen binding fragment thereof according to any one of claims 1-20. 35 37